Before you post a new thread please ensure that your question is not answered in another thread. You can use the search function to find threads. Also use the tags to find a topic.
To post a new thread first select the forum category. Once you have found it click on Create Thread.
You can now give a title, tags and your message. Images can simply be added by copy & paste or by uploading them as attachment. Once you are done click on preview to check before submit.
In the same way you can reply to a post. Write your answer or question and click on preview and submit.