I believe the monthly pass works out to be the best deal, at $42/month. You get access to all of their on line tools (recipes, cheat sheets, articles, shopping lists, recipe builders, restaurant guides, etc) and can go to as many meetings a week as you want. It's a pretty good deal. You can also ask to just sit in on a meeting for free to find out if it is something you are interested in.
THey also sell lots of products in the WW meetings...reference books, cook books, food, scales, pedometers etc.
But if you are used to doing things on line, there's really no need to buy anything extra.
The most important item to have is a WW calculator. You can either purchase one at a meeting (I think they are $12?), or you can download a free app.