I want to start using unity, but I need a free program to create 2D sprites. Any suggestions?
GraphicsGale is what I use. It has handy animation tools and can even create sprite sheets from frames.
I use a lot of programs free and not.
GraphicsGale as said above is great. It is easy to make spritesheets and animate your sprite.
PyxelEdit is great for making Tilesets
Tiled is a program that lets you draw with your tiles, to make levels and what not.
All 3 of those programs are free, if you google their names you can download them from their website.
I use Manga Studio 5 more than anything but that one is not free.