Hi and welcome to the guild. Just have a good ole browse around and post some new threads in the finished maps section if you have some to show off. You can start an album of your work here and you can post to map related links in other places. The best option is likely to set your signature and have the link to your main site there so that its attached to every post you make and also you can change it and it will update for all of your posts.

If your particularly pen and paper sort of art then that forum topic is a good place to discuss techniques and ask for help. I think most people use the "Whats New" and recent posts to check up on the latest rather than to hit up each topic and see the latest threads. So in a sense and in the short term it doesn't make a huge difference where you post it for day to day responses but for longer term keeping threads on topics grouped together will help you get more responses after a few days once the daily posts have rolled off of the bottom of Whats New.

You can take or offer commissions right from the start. Whatever you negotiate with clients is up to you and the guild is not involved with it so do your due diligence. If you want more people offering to chose you as a client then having a portfolio on this guild is a good idea. We tell people not to definitively trust images from other sites because there is no guarantee that they made the image. Its best if you pick a client where you can see that they have developed the work in stages - WIPs, or works in progress. Then you can be sure of their ability. So doing some threads on here showing WIPs gives confidence to people who need a map.