Here are two links, in case you don't like the forecast on the first one you visit.
Without doubt the best travel and activity insurance you will find.
For all those outdoor essentials.
Find out about qualifactions and much more.
There are two Railway stations within easy reach of Beddgelert, and an extensive local bus network (any problems in organizing connecting busses, I could pick you up from the Train Station);
For a complete list of all your options, visit the Beddgelert Tourism Website.