I've not been for a good few years now, but lake Bled is nice if you're taking the wife, absolutely stunning scenery, good riding out of the door, also boat hire/walking/beach (ish) good restaurants etc. Ljubijana is a nice place, but a bit like any city in europe, worth the climb to the castle though for the views. Hire a car while you're there as you can cover the whole country in a day, including alpine mountain top, inner city, black forest esque woodland and mediteranian type seaside. kranske Gorge is worth a journey if its still open (not for the feint hearted though!)
Union Pivo for the day, and Zlatarog for the evening!
(also, if you get the chance check out metalkorva for great free parties and loads of random rastafarians?) As for biking, no idea, and who to book with? No idea, I just showed up!