Although not as important for home users keeping your letters safe from your PC crash could still be a worry. The first thing to think about with backups is storage of the files. Work out a structure and keep it all in one folder whith sub-folders depending on the file. This makes not only finding the document you want easy but it means you can just backup one folder and all the sub-folders.

The easiest and cheapest way now to backup files is to CD. Do you have a CD writer or Re-Writer? A Re-Writer is better as it means you can use it just like you could with a floppy disk and keep writing to it. If you don't have a CD writer then you can pick up a cheap USB one. Blank CD's are also cheap now and backing up once a month is probably enough.