28 day tourist visas can be obtained from embassies of the Union of Myanmar. In London this takes about 10 working days so you should aim to get your application in as soon as possible.
How to get to Rangoon
There are still relatively few direct flights to Burma. Via Bangkok is still a favoured route. But there are now also direct flights to Rangoon from, for example, Singapore and Doha. Search the internet for deals. Overland into Burma is difficult but not necessarily impossible.
Where to stay
Accommodation in Rangoon is becoming more difficult by the day as tourist numbers increase. The Inya Lake Hotel, where the festival will be taking place, is already almost full. Again, the internet is the best bet to discover options. A number of agents come up on a Google search. These include Exotissimo, Golden Express Tours and Myanmar Travel.