One approach that has been used with success involves creating the constructing the chord structure first. A visit to the web site "chordie.com" links to thousands of chord and lyric combinations of most of your favorite songs. Note the structure of Band in a Box supports four bar lines. That's four bars of four beats per bar in 4/4 or three beats per line in 3/4.
In addition, typically, verse lyrics are twelve bars to the verse, eight or twelve bars per chorus. First, build the frame. Then add the body -- the sides and the roof.
You might look into the concept of "chord progression" while getting started. Typically, the changes follow a 1-4-5 progression. In key of C, the one is C, four is F, five is G.
Typical eight bar verse, Amazing Grace, John Newton, 1620
Line One
A (c) ma-zing (c) grace, how (f) sweet the (c) sound, That
Line Two
(c) saved a (c) wretch like (g) mee- (g) -ee.
Thanks edshaw, I can see how this can be very helpful when putting together a song, there really is a lot of help out there.
Just looking at the posts here, I cant help notice there are so many different ways to go about making a backing track, so its probably about finding the one that suits you best!!