Some of the earlier songs will be in different keys to the original music ( particularly the Beatles, who played in flat and sharp keys mainly ). In a lot of those songs, placing a capo on the 1st fret should do the trick.
For the songs added over the past few years, if I do transpose the song to a different key, I generally indicate this, and note the capo position.
I have a guide to song chord transposition at http://www.guitarsongs.info/transpos.htm
