hi! I recently acquired an old nishiki, which has been converted into a single speed. I haven't done much work on bikes myself (my father always did my bikes before, he is no longer with me, so I'm on my own this time), I'm really clueless at this point, not sure where to start. can any of you offer any tips for an easy conversion to fixed gear? anything specific I should know? any good sites with a tutorial? I'm kind of scared to do it myself, but I really want to learn. any help would be awesome.