Actually I think you might need a bit of clarity to help you decipher Peter's answer.
Most of this info is probably better explained in the manuals but here's my interpretation to try to get you started.

To set the transpose so that when you type in the chords from your Bb chart, go to the Notation display by clicking the button just near the right hand end under the double keyboard, labelled Not'n. On the left of the bar just above the notation, there's a button labelled "opt" for score options. In these options, right near the centre the transpose settings. You can select tenor sax, soprano sax, clarinet or trumpet from there to enable the correct setting for your needs (which is +2 or +14 semitones. The 14 though should only be important for melodies being written).
Now exit the options by selecting "OK" then exit notation window by again clicking on the Not'n button.

You can now type the chords you've got straight in - luckily the rhythm section transpose to their concert chord automatically from their so as far as I can see you can ignore Peter's comment "when you want to go back to piano, set it back to zero (concert)."

Also note there are heaps of standards available in Band In A Box format with the melodies & chords already set. The most common thing though is that the melody might need to be set not play through the solo choruses so to fix this, in the melody menu use the selection "kill melody choruses" & select "middle choruses".