If you are in Europe, this forum is a right place for you to share testing knowledge and networking.
Here is what they define themselves:
TEST (The EuroSTAR Software Testing) Huddle is a new online platform for software testers to meet with peers, access thought-leading content and to share and discuss their views on any aspect of software testing.
Even though TestHuddle forum doesn’t seem like the most crowded forum in software testing industry, their community are serious testers. So make sure you check out their guideline page before starting asking questions.
TESTHuddle also often shares free Webinars, eBooks and events there too.
What are you waiting for? Check it out
QualityTesting Forum was built in 2008 and considered one of the most reputable in software testing. You actually can find almost everything in software testing asked and discussed here.
If you are a fan of instant messaging, the forum also has a cool chat feature where you can chat with friend right there.