Yellow is a nearly illegible choice for a link color.
You need to identify what the purpose of the site is at the top. Otherwise you'll lose people as most make a decision to stay and use a site or leave and go elsewhere within seconds of landing on a page, and if they don't know the point of the site, why stay? You need to add a short tag line under the site logo that tells in a six- to eight-word maximum phrase what the point of it all it. Don't expect people to stop and then read through all the forum sections to try to figure out why they might want to be here.