So what kind of blackberry do I get if I want internet for my laptop?

So what kind of blackberry do I get if I want internet for my laptop?
I don't know anything about cell phones, or plans, but I heard since a blackberry has wi-fi you can hook that up to your laptop and get internet from the service you pay for anyway. Which is the good kind of blackberry that enables that or any other cell phone with the same capability? Also how I make that work and how do plans work, etc?

also w/o at&t service since soon they gonna charge their users per bandwidth instead of service plans, which would be more expensive if you use your cell or internet a lot.
valentine's day gift.