Find 4 or 5 people that do the same sort of work that you do. Collect their e-mail addresses and send a group e-mail introducing everyone to each other.
Ask them a question you need help with. Ask them what problems they have, then help solve them. Keep the e-mail list going. Keep it short and valuable.
Add a few others to the e-mail list. Use the e-mail list until it becomes cluttered then move to a forum. Give people with a special expertise their own sections.
Let more people join. Solve more problems. Share more advice.