hey hey i've played bass for 10 years now i think starting on those big stand up violen types. If you've been playing guitar you should allready know all your major and minors and then there just same on bass right well the lower 4 strings are the exact same as what you've used on your quitar so the paterns are all the same. I have this book that shows me all the harmonic and melodic version of the scales it was really cheap but i'm sure you could find those online.

http://www.mxtabs.net/basstabs.php

thats the site i use have all the tabs you could ever want plus cool little leason's on techniques like slaping and tapping.

http://www.youtube.com/watch?v=Jw8ytGHTbNc

watch that guy play try and slap that quick someday