For those who are having issues with the new forum here is a screen shot of an easy way to get to your favorite houzz forums.

When you are on the page of all the available topics you can hover your mouse over the category and a follow button will appear. Click on the follow button and your choice will then be saved on the left of the screen under "Your Topics" heading. You probably have to be signed in to save the categories, however I did not try it without signing in. It takes a few minutes if you are looking to save a few categories, but makes it so much easier later. Once they are saved you just simply click on the forum you wish to see. Hope this helps.