Staples sells its "Eco-Friendly" brand of paper, made from bagasse -- the plant fiber waste from processing sugar cane and although thin, it works really well. And cheap.
No bleeding, showthrough, or feathering. Get some and try it, you will be amazed.
The Staples notebooks/pads are definitely a great starting point. I was lucky enough to learn about them when they were on sale for a little over a dollar apiece!