Welcome! I have been a registered user for about two months. I stumbled onto this site and I now can't imagine what I would without it. It has been a really helpful guide for me for all kinds of things. I would suggest to take a big chunk of time, when you can, and just click on different areas of interest and do some "exploring". There is so much here that it probably will take you hours (I spent almost eight the first night I found this!) or days depending on your time constraints.
What I have most useful on a daily basis is checking in with the new posts---I like to welcome newbies--, the calorie counts of over 7,000 foods, the different diet plans and how they work, then the different sub-forums groups.
For structure I am working the WW Flex Points plan, I have devised my own workout plan according to my needs and schedule (treadmill, free weights, Pilates and dancing dvds), I keep a food diary, exercise chart and weight lose progress chart (you can get "shells" on here or other links), I made a promise to myself that I would check in with this website to give and receive support at least once a week but it has now become more like 3x a week (I just like to read the inspirational stories and "be there" for others), and I am still "educating" myself on other plans as well.
Good luck on your weight lose-----