I think FAF could do some valuable work, but it needs to focus on one area - the BNP and local traditions. It may be helpful to explain what FAF stands for and demonstrate how supporters can help make that stand. For instance:

Can I in the spirit of real friendliness suggest you read the thread where you will find all the information you need - including websites. Then type Folk Against Fascism into and take a look at the Facebook page. You don't need to be a member of Facebook to read that.

Then you can seek out local anti-fscist groups (most areas of the country are covered) and join that. You'll find they will be very helpful.