We get a lot of suggestions on how to improve our documentation. it's certainly an area we take seriously, and plan on investing a lot of time and effort in in the upcoming releases of the .NET Framework.
There's an opportunity to be a part of this team, and work directly with the CLR product teams to define the documentation for features, and functionality exposed by the CLR. You can apply directly to the opening here.
I would note something here as my own advice when looking for this position (by the way, the advice is similar for other positions at microsoft). Do read through the set of functionality listed at the top of the job posting (memory management, garbage collection, etc.), and see what things you ACTUALLY are interested in. The position won't be for all of these areas, but responsibilities can often be shuffled around if you have a particular passion/expertise, to match a slightly different job to your skills. If it can't happen immediately, it's a really good idea to share where you want to be! It also demonstrates you've read through the position, and thought about how it fits you, and WHY you applied for the job.
Feel free to contact me if you want to ask any questions about this kind of position, and want some insight: email@example.com