Frankfurt International Airport is a major hub, so visitors flying from outside of Europe will normally pass through here. If travelling from the UK, there are a many budget airlines servicing the major cities and regions.
Arriving from neighbouring countries by train is a more relaxing way to travel, although you may need to book ahead at peak times and on public holidays. For train times and prices see the Rail Europe website.
You probably wouldn’t need to book internal flights in Germany, as the rail system is fast and efficient. If you do have to fly across the country Lufthansa has the most comprehensive network.
The Germans sure know how to run an efficient train network. Most of the country’s trains are run by Deutsche Bahn (DB) and you can pretty much get anywhere you want.
If you can’t get there on a train (unlikely) you can probably get there on a bus. In larger towns head to the main bus station, the Busbahnhof, where tickets are sold by the bus companies.