As far as I am aware, the only major glitch needed for Sonic 2 rings is the screenwrap glitch in Metropolis (and you shouldn't try that first anyways). Oh yeah, and the minor glitch in Oil Ocean where you can spindash under the pillars in the oil. The best way to do any of those is to take the map for the level and draw for yourself what path you're going to take. Some of them can be kinda complicated and drawn out (OK, sorry, maybe all of them) but they're not too difficult once you've done that. Definitely save Oil Ocean, Metropolis, and Wing Fortress for last on these.
Oh, and warning you now: Hill Top 2 with Sonic is a ROYAL PAIN. The current record involves reaching nearly the end of the level on the "upper route" and backtracking as far as you can on the "lower route". Unfortunately, since you've gone backwards, the gondola-basket-type-thingys are in their highest positions. The result is a set of blind jumps over lava to get five rings in midair. >_< Plus this is at the end of the level - every time you mess up you have to start over. Oh yeah - and you still have to fight Eggman after that. That one almost made me cry trying, but I did it.
I once had most of the records, but unfairly due to personal misunderstanding about the rules (Mega Collection Plus savestates). I've taken (in my mind) some of the most difficult ones back, but from what I can remember, Emerald Hill 1 and 2 I did quite easily without a map or savestates. (I still took the stats down just in case.)
