to book trains or buses on-line. I plan to go from Konstanz to Freiburg im Breisgau, then to Baden-Baden and then Heidelburg and then finally to Munich. I had hoped to go to Ortenburg but couldn't find public transport to the Hostel. Also how do I find out the station that is closest to the hostels.
Wyando just directed me to this thread ;) Seems I have some reputation as the resident public transport geek. Not without a reason, I have to admit.
It is usually not necessary to book trains or buses in advance in Germany. You might get a better price for prebooked tickets, but only in long distance traffic. For shorter distances there is no reason to buy a ticket in advance.
As long as you stay within of the state of Baden-Württemberg - and all places you list do that except of München/Munich - the maximum you really have to pay is 21 EUR. This so called "Baden-Württemberg-Ticket" is a daypass valid from 9 am (Mon-Fri) or all day (Sat/Sun) for all _local_ trains, buses and trams within of the state and sometimes a little bit beyond. It is _not_ valid on the fast long distance trains (IC/EC/ICE/TGV), though. They have their own pricing scheme and usually are much more expensive. Of course it's not always the cheapest solution to take the Baden-Württemberg-Ticket, and not always the best solution to restrict oneself to local trains, but it's an upper limit for a necessary price. And it always includes the city bus.
For the trip from Heidelberg to München, IMHO a prebooked "Sparpreis" discount ticket on a fast train would be recommendable. It's possible to book them online if you own a credit card. Prices start at 29 EUR but vary between connections, also these tickets are subject to availability - there's only a limited quantity for each price level. Prices for "Sparpreis" tickets generally raise 14 days before departure, and latest they can be booked is 3 days before departure. After that, only the higher standard price is available. If you tell me when you need to go, I might be able to recommend you something specific, and maybe even get a few euros of additional discount for you.
About public transport to the hostel:
http://reiseauskunft.bahn.de allows you to enter adresses instead of stations for an itinerary. The computer will then try to find a station or bus stop in reasonable distance by itself, and even display a map of the remaining walking part. However, the results are sometimes a bit weird, and sometimes these connections won't really work, so it might be a good idea to let someone double check them. It will give you a hint where there's a bus stop nearby which has useful connections at least.
Please note: I'm not going to read this forum or just this thread. I don't plan to attend the convention either. So please send questions by mail/PM if you want an answer ;)