Good Evening there! So a group of us (4) want to visit Europe. We are active duty Marines so we only have about 15 days to do it.

We are looking at the end of September to visit Oktoberfest in Munich.

We are looking at

Munich, Germany (Oktoberfest)
Zurich, Switzerland (Sky diving)
Rome, Italy (Collosseum, Forum, Vatican)
Paris, France (eiffel tower)

We will only stay a few days in each place, we are looking to visit the main items in each place.


So my questions are
1)What do you recommend as far as taking the train or flying to each city
2) Other recommendations in each city
3) Cheap hostels to stay at
4) Which city to start at and hop to the others.
5) Anything you think I might need to know.

Thank you for all your help and time to answering my questions.

Fly open jaw but obviously you thought of that.
Munich Zurich look at train. Seat61.com is helpful it seems.
Then look at kayak.com for internal flights. Lots of low cost flights. Book direct with the airline.

Have a look at the Let's Go Student Guides. They have a ton of info on budget travel in each of these places, info on where students/younger travelers hang out in clubs or pubs, active travel info and also info on hostels. Be careful about the latter - many are fine but some are in in poor locations and/or have problems with drugs/theft, etc.

Skyscanner is good for cheap flights within europe - just be sure you understand the specifics on luggage and check in for each one - some are very onerous. Most of your cities are too far apart for train to make a lot of sense.

There are quite a few budget airlines in Europe. Try Easy Jet between Rome and Paris (Orly airport).

http://www.easyjet.com/en/

You might check the train between Munich and Zurich to see how long that takes.

Fly into Munich, train (fly?) to Zurich, train to Paris, fly to Rome, fly home from Rome.

If you book trains online, buy tickets from each departing country's train company.

Germany
https://www.bahn.de/p_en/view/index.shtml

Switzerland
http://www.sbb.ch/en/home.html

Maybe start in Rome, you can get very cheap flights to Zurich. Train or drive to Munich, where you can get very cheap flights to Paris. (Yes be careful, the budget airlines are very strict with luggage weight & size so read the fine print.)

With 4 persons, hostels don't always work out as the cheapest places to stay.

Lodging:
Rome: Il Piccolo Aventino @ Via Pirro Ligorio#8
Zurich: Swiss Star Center @ #4 Aussersihl
Munich: Maybe Hostel Haus? Hmmmm, Munich will be expensive during Oktoberfest for sure.
Paris: Au Royal Mad or Hostel Eiffel

I don't know how much you want to spend on accommodations, but you might look into renting an apartment in each city for the four of you, presumably for three(?) nights in each place. It might work out better than a hostel, and if one of you can cook, you can save money on meals.

Good luck, and have fun.