At the moment, all i can suggest is to download or 'Torrent' photoshop (dont spend money on it as you will be spending hundreds on something you can get for free)
A torrent is just another version of downloading, which if you want... i can explain more in depth via pm.
Basically, photoshop is editing software ... think of it as a special paint pallet that you can use on your photos. You can make it darker/lighter/more colourful/change the colour/put other pictures on top of it and make it transparent
the list is endless...
I'd suggest downloading 'Photoshop CS3' CS3 is just the version, nothing special or complicated. You then use something called a 'Keygen' to create a serial code (much like the one for diablo2) so you can use photoshop anytime you want. Adobe arent actually selling CS3 anymore , which is why i suggest you download it

*your other option is to buy CS4...which will set you back ALOT of money*
As for using photoshop... there are many tutorials on youtube if you have a look, they will teach you anything you want... also, as im sure your aware theres alot of people on jsp willing to help you.
If you have any questions, please just pm me (i taught my mum how to use her first computer, so i really dont mind helping) ... as i will respond to them alot quicker.
Anyway, photoshop is great fun and definately worthwhile. Should open up a whole new window for you and your photography.