I'm a digi scrapping addict lol. Well at least I used to be it's been a wee while. I use Photoshop version 7 but I know of a lot of people that use GIMP which is a free programme you can download http://www.gimp.org/ Personally I've not used it but apparently it's a good place to start. Here's a list of a few place you can download free digi scrap kits from. It's a bit hit and miss with free kits occasionally you find something fab but mostly they are duds. You just have to have the patience to trall through the crap lol.
http://www.digitalscrapbooking-free.com/
http://www.craftcrave.com/
http://www.raspberryroaddesigns.blogspot.com/
http://digital-crea.fr/shop/index.php?main_page=product_info&cPath=65&products_id=7583
Now for the good stuff :) Much like normal scrapping if you want to do it well you have to buy kits. Freebies are great for practice but if you want to make an awesome page you need decent kits to work with. So here's a few links to my fav sites that I buy my kits from.
http://www.shabbypickledesigns.com/boutique/home.php
http://www.afterfivedesigns.com/shoppe/home.php
http://digital-crea.fr/shop/index.php?language=en&main_page=index
http://www.scrapbookgraphics.com/
After five designs is my absolute fav! Here's a couple of pages I made with kits I've brought.