You need to got to the Marriott Vacation Club International web site, or call a Vacation Club advisor at 888/682-4862. I convert most of my weeks into Marriott Reward points every year and have had some great vacations between Marriott hotels and the time shares. Also, look into travel packages, probably the last great deal offered by Marriott Rewards.
Are you referring to Marriott Reward points or Marriott Vacation Club Destination points. If your weeks are enrolled in Destination Club, you can convert to DC points and use them for nights at other MVC resorts. These can be a fair value and are very flixible.
Converting to Marriott Rewards points is no longer a good value. The amount of MR points that are provided for your week haven't changed since the program began several years ago. However, Marriott has significantly increased the MR requiremetns for a stay. When I purchased my timeshare in Orlando, 110k MR points would get me 7 nights at any hotel/resort worldwide, air fare for 2 on major airlines, a Hertz full size rental for a week, and a cruise certificate. Now, the same amount of points will get me a 5 night stay at a Courtyard. During that same time, my maintenance fees have also increased from about $350 to $1100.