Don't be afraid, everyone learned it some time. My 70 year old grandma just got online this year, and she's doing great.
For picking up basslines I recommend going to the following website and finding a tab (i.e. a written-out bassline) :
www.ultimate-guitar.com
On that page type the name of the song you want to learn into the search box and hit enter. Then a list will come up with tab files that match your search. Find the one by the original band (sometimes remakes get made into tabs) that is for bass and open it up by clicking on the song name. An advertisement window will pop up when you do this, it's normal but annoying. Go back to the window with the tab by closing the ad window. Back on the tab page look for the "print this tab" at the bottom and click that. It will make the page ready for printing, which you can do quickly by pressing the buttons 'control' and 'P' at the same time.
Now using this as a guide, play along with a CD to practice, refining as your ears tell you.
Hope this helps
