The UKWA is an organisation for competitive windsurfing, but for those looking to learn for the first time:

Windsurfing Level 1 Courses

Your best bet is do a “level one” course with an RYA centre, then practise for a bit at the centre trying their hire kit out a couple of times.

The RYA

The RYA is the governing body for all Windsurf schools, and oversees the general running and safety of all centres. Please visit RYA web site for local centres.

Coaching

For those looking to advance more quickly, competing with the UKWA is an excellent way, but for added advantage there is a database of Windsurfing coaches.