Teams
There are hundreds of teams within the UK all willing to accept new players or teams looking for more experienced players to help them get higher up within the UK ultimate scene. A lot of people start playing at university as most now have a frisbee team so if you are starting Uni do some research and I'm sure you'll find a team to play for. If you aren't starting Uni you should still do some research and you'll be able to find a team within travelling distance from you as the sport is expanding rapidly within the UK.
Here is a good tool to find teams in your area: www.ukultimate.com/teamsmap?tid=All&city=
Duffa (Didsbury Ultimate Frisbee for Amateurs) - A great team that introduces ultimate to amateurs within the Manchester area. They also do a tournament in summer which is extremely popular and encourages beginners to come play, it is a non profit tournament so plenty of cool prizes and such.
Clapham - Probably the best team within the UK and one of the best in Europe, based in London they regularly go and win outdoor tournaments in the UK and compete against some of the best teams in the world.
Chevron - Another team that competes at a high level not only in the UK but also in the world. Haven't managed to beat Clapham at nationals...yet.
Man UP - Another team based in the Manchester area who are always looking for experienced players to help enhance their squad.
EMO - A team based in the east midlands who compete in the top 16 teams in the UK in the tour events over summer.