The Internet is full of sheet music, now it may not be correct, and it may not be what you want -- tab for 6 string guitar would not help me with a bass line. I would want bass cleft standard notation or fake chord or lead sheet showing the chord name and yes, armed with only the chord name then I would decide how much of the chord to include in my bass line.
http://www.google.com/search?sourcei...+Va%2c+Santana
For example the fake chord would show a C7 chord, OK I know that is a chord tone of R-3-5-b7 now how much of that I use depends on what it takes to get a groove going. Perhaps only roots will get it done, then perhaps R-R-5-8 would fit this song best. Yep that is going to be left up to you.
Good luck finding bass cleft standard notation on pop, rock, or country on the Internet. Music store will probably have piano sheet music you can buy. Your best chance is going to be able to play from fake chord or lead sheet. Which only list the chord name and leave how you play that chord up to you. Talk to your instructor and your music store owner.
Good luck.