I would check with your local musical instrument shop as they could offer advice on which amp to use. There are amps specifically made for the use of Bass guitars. I am not a bass player but a drummer, but I have jammed on occasion and my friend the bass player was tight for cash and rented a bass amp until he could afford to buy it out. This way he could pick the amp he liked the best for sound and any options that it possessed that he was looking for.
As far as transcriptions for bass, magazines specifically for bass players are the best route as the internet transcriptions do run the risk of being inaccurate and limited. Too many guitar players out there that bassists and drummers kinda have to figure it out on their own, which isn't a bad thing, 'cause you can learn a lot just taking the time to play around and try new things. I guess it is easier for me to learn by ear, but bassists can as well.
Good luck and don't give up, it is a fun hobby that can quickly turn into a passion.
