When I first started I was:

1) amazed at the wealth of knowledge already available

2) astounded by the wealth of knowledge offered in answer to questions (and the speed at which it was offered)

3) awed at the expertise of many of the posters

4) totally floored when people took me and my responses seriously.

Not my first experience with an online community. One of which was welcoming - three or four of which I backed out of because they were definately clique-ish and one which was hostile to newcomers.