Blackra1n newbie, help?

[Candy Hearts]

i have the newer generation of Ipod Touch and i dont know much about Blackra1 except that it gives you all freedome to you ipod =D. Right now, my ipod touch is having that stupid problem where you download apps and it goes on for like 2 seconds then takes you back to the home screen. and the worst thing for ME is that i dont get my computer in which all my stuff are in until later tonight, im not sure if the restore is going to work or not..okay back to Blackra1n. i've watched a video on how to jailbreak, just like download with ipod connected and press Make it Ra1n or somehting like that. But i have many questions to that. 1 of my friends said theres a problem with blackra1n, and he didnt tell me what but anyways i keep seeing and hearing that if you use it on iphone 3g or 3gs then theres gonna be a problem, in anycase, they said NEWER VERSIONS. so does that concern my ipod touch? oh yea and its new =D.
Will my songs and stuff be erased?
Will there be any difference at all after jailbreaking? or will it be EXACTLY the same except for sweet freedome....-day dreaming-
please help =)