There are two ways to do this.
1) Click on a category under the forum topic that is most relevant to your post. Then simply click on the Post Thread button towards the top of the page on the right.
2) When you enter the forum, there is a Post Thread button towards the top of the page on the right that you can click.
On the pop-up window, choose which forum you want to post in.
Give your topic a subject, and then enter your text in the message body. You can also opt to watch your post and get notifications before you post it. When you are finished, click on the Post Thread button near the bottom of the screen.
1) Click on a category under the forum topic that is most relevant to your post. Then simply click on the Post Thread button towards the top of the page on the right.
2) When you enter the forum, there is a Post Thread button towards the top of the page on the right that you can click.
On the pop-up window, choose which forum you want to post in.
Give your topic a subject, and then enter your text in the message body. You can also opt to watch your post and get notifications before you post it. When you are finished, click on the Post Thread button near the bottom of the screen.