Find the correct forum for the subject you wish to discuss - click to go inside the forum. Check that the topic doesn't exist first. To start a thread - click the 'New Thread' button situated left & top/bottom of the forums page.
Please give it a 'descriptive' name that sums up in a few words what you wish to discuss on this new thread. Then type what you would like to discuss - giving as much detail about what you would like to discuss in the first thread. If it is too vague, other people will misunderstand and post replies that seem out of place or not what you wanted to discuss.