Welcome to our World. It is a journey best taken one step at a time. Helps if you do have a road map. A place to start and some directions along the way.
No question an instructor sitting knee to knee with you is the best way to go. If that is not in the cards, then get an instruction book and start on page one. I recommend Bass Guitar for Dummies. Here are a couple of pages from the book.
http://www.dummies.com/how-to/conten...eat-sheet.html and then the Internet site
www.studybass.com is worth your time. Here is an example of what you will find.
http://www.studybass.com/lessons/com...nth/exercises/ Both are good, follow a logical order and cover everything you need to get started. I bet your public library will have Bass Guitar for Dummies.
The bass is a little different than your rhythm guitar, we both play chords, but, we go about it differently.
Yes you need to know where the notes are on your fretboard. One important thing to keep in mind is what type of sheet music will you be using - that dictates how you will go about finding those notes. If you are going to play from standard notation you need to be aware of the note name and where the notes are on the fretboard. If you are going to use fake chord sheet music then the interval number becomes important and the major scale box pattern becomes a friend.
I think the following will give you an overview of what to expect.
http://www.talkbass.com/forum/showth...67#post9372867 http://www.guitarhangout.com/wp-cont...itar-notes.jpg http://www.smithfowler.org/music/Chord_Formulas.htm http://www.cyberfretbass.com/scales/basic/page2.php
See what you can do with this play-a-long
http://www.youtube.com/watch?v=bUK5pE5x_6A four A's then four D's, etc.
Those sites will give you more information than you will be able to process right at first, but, should give you an idea of what lies ahead. Ask specific questions here.
Good luck.