Working is not enough: you should work optimising your resources, with the aim of saving your time and efforts, as well as avoiding being overwhelmed by all the stuff stored in your PC: working files, invoices, reference documents, application and program manuals, etc: believe me, they pile up very rapidly and cause a real chaos, if not kept under constant control.

E-MAIL

First of all, unless you keep in order either incoming and outgoing e-mails in a timely and appropriate manner, they will turn to be a real problem. Since we all work almost solely via e-mails, we should organise them so to be able to track back the relevant communication quickly, if needed.
First step: create separate folders, each dedicated to an 'important' customer, i.e. those whose working relationships are frequent and well-established. After creating such a folder under 'Incoming mail', you should create some redirection rules for the e-mails, each for each customer, so that every time you get an e-mail from a certain address, it will be automatically redirected to the relevant folder.
That way, you will also get a visual order, as you will see all the new incoming e-mails marked as non-read and contained in their folders.
All the rest of the e-mails not redirected to any folder, will remain in the generic incoming mail folder.
Now, you should get rid of spam, a real trouble: it is not a 'mission impossible', you should simply install an anti-spam program (e.g. Cloudmark – I tried it and it is very efficient). It works using the mail redirection method: each time you get an undesired e-mail in your incoming box, you have the option to block it using the Block feature of Cloudmark so that next time you get an e-mail from the same IP address, it will be automatically sent to the Spam folder, from which you can simply delete it. Besides, Cloudmark detects spam through certain words contained into the e-mail Subject line, so you would not even need to redirect these e-mails, as the program will take care of them automatically.
Now, you can proceed to review the remaining e-mails contained in the generic incoming mail box, deleting those you are not interested in - even if they are not spam - and leaving as Unread those you intend to review later.
As already said in a previous article (see 'How valuable time can be to a freelance translator and how to organise your workday and life' downloadable from my website and from Proz.com and TranslatorsCafè), it would be a good idea to organise your e-mail program by setting an automatic reply message so to provide a reply to anybody contacting you during your PC shut-off times, or anyway when you cannot attend the incoming e-mails immediately.

In conclusion, every now and then – maybe each end of the year - you should clean up the e-mail program storing all incoming/outgoing e-mails on the PC or a removable hard-disk device. That way, you will not delete them, and you can always track and consult them in case of need in any moment to rescue important information. To do so, you should simply install a program such as DBxtract – I installed version 3.8 last year, but now also v. 3.10 is available. This program allows you to extract e-mails from Outlook Express, for example, and to backup them for storing purposes.

WORK FOLDERS

Order is important for the work folders as well. So, the basic operation you should carry out is the same already described for the e-mails, that is first of all to create a Main work folder, then a customised sub-folder for each client to save your incoming and outgoing translations.
After that, I recommend to create two further sub-folders under each client's folder, one for the original job and the other for the job to translate/translated. It is always advisable to save at least one copy of the original file, in case of any 'disasters' or crashes (e.g. file containing corrupted tags that Trados cannot handle, so you often have to delete the corrupted file and use its original copy.) Besides, sometimes you need to create additional sub-folders to save a Translation Memory supplied by the client, or some reference and consulting files, etc.
Do not forget to create a Quotes folder, where you will save all the jobs without a definitive PO and that you need to have temporarily at hand in order to prepare a word-count and a quote.
Anyway, with this simple operation you can keep everything under your control, without the risk of mixing different files and/or losing anything.
INVOICES

Of course, you have to create as many sub-folders as your clients for the Invoices folder as well, as in the case of the Work folder. All invoices issued during the year are to be stored there.
First of all, you should create two main folders named Issued invoices and Received invoices. The former will contain any invoices issued for the jobs made, while the latter will be intended for any invoices you receive from collaborators who worked for you.
As for the folder containing the issued invoices, I would recommend to prepare some customised invoice templates containing all the client's data, such as the header and the address, leaving a blank space for the lines/boxes indicating the job number, the word-count and the unit rate calculated on a word/page/hour basis and, of course, the total amount of the invoice.
The Invoice main folder could also contain a PO sub-folder dedicated to the job orders received from your clients. Effectively storing the PO's consists in the immediate filing of the order as soon as it arrives, and then printing and saving it on paper so you have it on hand either for consulting purposes during the translation process – PO's often contain specific instructions - and to recover data for invoicing at the end of the month.
While you usually do not consult issued/received invoices and PO's very often (so, it is sufficient to store them), a somewhat useful operation is to keep a synoptical table summarising your invoicing status. The table for the issued invoices should contain the invoice number and the client's name, the issue date, the invoice amount and a blank column for any notes (e.g., paid, pending, etc.). As for the received invoices, you can follow the same scheme.

Talking about archiving, it is a good idea to keep an e-archive for the payment of taxes. As soon as you have carried out an online payment, you can save the relevant receipt on your PC. To do that, you have to create a folder named, for example, Tax receipts.

SAFETY

Archiving, by means of periodical back-ups, all your material – either work files and invoices, PO's, payment receipts and TM's – is the first step to guarantee your work is safe; of course, it would be advisable to backup the entire system every now and then. You should carry out these procedures as an overall disaster recovery policy on a regular basis.
Backups can be carried out in several ways: removable hard-disk drives, fpt areas physically outside your house - in case of fire, at least your work will be safe - CD-ROM's and USB keys.
It is advisable to browse your folders on the PC and 'clean them up' - that is, zipping the files and deleting any useless copies there contained - before proceeding to trasfer them to any backup drive.


Daily Backup:
at the end of each working day, you should backup the ongoing works and the relevant TM's.

Weekly Backup:
once a week, you should backup the files of the works made in that week and their TM's.

Yearly Backup:
once a year, you should archive all the invoices issued/received and any payment receipts of the year just finished.

As for the backup ftp areas placed outside your house, it is a good idea to use them to carry out the backup of the whole system, in case of any irrecoverable damages to your PC. Google, Yahoo, Gmail and others provide many offers of backup space.

When talking about PC safety, all of us immediately think in viruses, trojans 'et similia'. Therefore, we need a good antivirus (such as Norton Pro) and set it on an automatic daily scan, for example at 8:00 p.m. once finished working, so the scanning will not slow your work.
Another way to protect your PC from outcoming attacks is to install a program such as ZoneAlarm, that performs a continuous scan it – especially if you have an Internet non-stop connection. Acting as a firewall, ZoneAlarm blocks any incoming intrusions.
Finally, there are many anti-spyware programs, some of which freeware (eg. Ad-Aware); you need to run them at least daily in order to eliminate from the system any spywares - more or less dangerous - that entered your PC.
If you use Linux instead that Windows, the entire issue of viruses etc. is simply non-existent!
Of course, keeping your PC tidy also involves operations such as the physical elimination of useless and duplicated files. To that aim, it is sufficient to run a weekly disk cleanup to eliminate any backup and temporary files stored during the week.
Less frequently, at least once a year, it would be advisable to carry out a defragmentation, which reorganises the hard-disk and recovers valuable free space.

I hope these brief guidelines may help you and invite you to send me a feedback indicating any missing or not completely developed points in addition to the ones here exposed.