1) The "What's New" page on the homepage of the community (just click "PC World Community" in the bread crumb trail) will give you a reverse chronological (newest stuff at the top) list of everything that is new across the entire community. You can use the "Your View" button at the top of that page to customize what is in that view. For instance, if you never want to see posts from the Mac forum, then you can remove that one from your list.

2) Within each community, there is a similar list for just that community. So if you want to see what's new in the Windows forum, you can go into Windows and look at the All Content tab for a reverse chron list of new items there.

3) When looking at a list of content in a community (say, Windows), the items in bold are ones that you have not read yet. The ones not in bold are ones that you have already read. The forum marks anything older than 30 days read. I can adjust that setting, so if you want more or less time than that, let me know.

I will have to investigate the signatures -- this is a functionality that we added, and I'm not sure if it takes HTML or other code. I've added it to my list of things to check on/work on/fix.