Photoshop
Adobe Photoshop is renowned for its versatility, but this means it is very complicated and expensive (up to £560 for v7.0 full version) for the average person to use. Photoshop LE, is a cut-down version of the full product, good enough for most photo-editing tasks, but a serious omission is the lack of the "gamma correction" routine in the Windows Control Panel. I know it is often packaged for free with some scanners and printers but, considering that gamma correction is the probably the most important component to aid successful image reproduction, how on earth do Adobe expect people to get good results and then want to upgrade to the full product? Well they now have. With the release of Photoshop Elements gamma correction is now included.
When the system is correctly calibrated for colour (using the full product), you can just use the basic functions in Photoshop and get a good photograph, but this is an expensive way to do it when there are other much cheaper editing packages around, for a fraction of the cost.
Should you want proper printed reproductions, not using an inkjet printer, then Photoshop is the industry standard and you will need advice from the printer as to how the files are to be saved, including any ICC profile information, CYMK separations, crop marks and registration.
My advice would be to look out for genuine liquidated stock (full) versions of Photoshop at a computer fair. or an earlier (full) version at a sale price, which you can then upgrade.
Photoshop v5.0 LE used to be supplied with some items of hardware, such as the new Epson 1290 Photo inkjet printer. Since version 6 Photoshop Elements is often included instead. Before splashing out on any version of Photoshop see if you can save money by buying a scanner or printer bundled with a version Photoshop you can upgrade.
If you only have Photoshop v5.0 LE, then you cannot cheaply upgrade to v7.0 without paying firstly for an upgrade to v5 (full), then another upgrade to 7.0 (full). Each of these upgrades can cost around £150, but please check with Adobe first. You will have to ring Adobe for price of the upgrade from LE or Elements to the full version, as this is never listed on the web-site.
One word of caution, a number of friends have had problems with delivery of the upgrades when ordered directly from Adobe, in fact they cancelled the orders after countless telephone calls (sometimes to Adobe, sometimes to the delivery firm employed). Be careful if ordering from Adobe to include postage and packing, which is not made very clear and resulted in one of these complications. I ordered my upgrade (v5 to v5.5) from Technomatic and was very surprised when it was delivered by courier the very next day. When I ordered v7 upgrade direct from Adobe, again it arrived next day.