research! go to srswap.com and read, go to freshalloy.com and nissanforums.com, sr20.net

you've made a great choice, the B13 SE-R will make a very fun car for a reasonable price. They are great fwd project cars. theres a ton of information available online, and the engines themselves, if sourced from a reputable dealer will serve you well.

If you have any questions, there's plenty of people here on TR that can help you. Just try not to ask stuff thats silly and easily looked up.