What kind of beer for beer bread?
I've used dark beer with good results. It just depends on what flavor you desire.  I often use Lion stout, for example, which imparts a strong, intense flavor and color, which I quite like, but it would not be appropriate for all applications.  Also Sierra Nevada porter has happily found its way into my bread. Keep in mind that these beers may be too strongly flavored for your taste, in which case you can add some lighter beer to balance it out (lager or pilsner). 

Personally I don't like to add pale ales to bread as I don't enjoy the way the hop flavor comes through, but this comes down to personal preference.

In general, the flavor of the beer will come through in the bread, but you won't notice all of the subtleties of flavor that you do when drinking, so I wouldn't put too expensive a beer in bread--the bread will turn out fine, but you're not going to appreciate the beer to its fullest.