I really enjoy Remington Gun clubs. Keep an eye out at Dick's Sporting Goods or similar and you should be able to get them for under $5 per box.
Nothing wrong with the Federal Top Guns either, I have used a lot of those as well.
I would say shoot whatever is cheap. Practice is going to do a lot more good than ammo. As long as your gun feeds it, it is good to go. Enjoy the new addiction. You should give skeet a try if you have that in your area as well.