Your material would depend mostly on what YOU enjoy playing and what kind of audiences and venues you want to play for.
There are a lot of good lyric sites where you can get ideas...and many of them are classified by genre.
For instance, for pop music from the 40's on
http://ntl.matrix.com.br/pfilho/summer.htmlis very good.
There are similar sites for Country and Big Band music.
To look at historical charted hits http://www.billboard.com/bbcom/charts/yearend_chart_index.jsp?JSESSIONID=5KGcJ2HGxsx6lp7pxSWftyT81MhLVvxKpg3nP01vsgGwww0GNfvq!1928910084
will give you song names and their artists year by year.
Visiting venues and seeing performers is also a great way to see what audiences like and to get ideas.
Good luck,
Eddie
[This message has been edited by btweengigs (edited 01-20-2009).]