There are many activities that a university entrepreneurship club can organize in order to help the students become entrepreneurs. Mainly guest lectures that either speak about their personal experience or professional lectures that talk about specific subjects (idea generation, legal matters, raising capital). In addition, you can organize field trips to interesting startups, VCs and businesses in your area. Once you have enough people, you can organize competitions, such as elevator pitch or business plan competitions.
The key factor is getting enough people committing to the club. You don't want to organize a lecture, and then find out that the room is almost empty. That requires a lot of marketing work, and it doesn't always work out. One way of reducing the risk is opening events to outsiders, especially students from neighboring universities and their entrepreneurship clubs.
The most important function of the website is to help with the marketing of the club events. What seems to work best is to have a blog with interesting articles and a calender in the main page that includes all the club events, as well as related events in the area that might be of interest to your community (such as events from neighboring universities).
I would not add a forum at first, since a dead forum is much worst then no forum. Add links to your facebook and linkedin groups, and advertise via those websites and a mailing list you can build. Expect that 5-10% of the people that confirm their arrival to an event in facebook will show up (that has been my experience anyway).
One more thing, don't make your club a one man show... Find a management team that will help you, even if you can handle everything yourself. If you want your club to exist after you graduate, you need continuity, which means you need a number of people that can replace you. If you choose one successor, and something comes up, a club without a head cannot exist. I have had a successor quit because his girl friend died in a plane crash, and another didn't handle the internal university politics well and almost got the club shut down while I was on exchange to another university. Things happen, and you need a team that can handle things as they come.
Good luck, and feel free to ask for advice (I have a soft spot for university entrepreneurship clubs :) )