I usually update my table of contents once I post a new chapter. When the chapter has been posted, I click on the chapter-number in the upper-right corner of the post (something like '#37'), which will reload the page, and insert the direct URL of the post in the browser's URL line (usually somewhere above the web-pages you see). You can copy that line and insert a link with that URL into your first post. Easy as pie
The post link opens the post in a full page. I've started changing the "viewfull" tag near the end to "posted", which causes it to open the thread, jumped to that post. This makes it easy to jump to a chapter then read on from there.