I have contributed several pieces on subjects I know a bit about (bios of Max Malini and Paul Rosini; brief history of "The Asparagus Valley Cultural Society"...) ...
As well put by ElMystico, not being an "expert" on other topics (hardly an axpert on the above either, truth be told) I have held off, because whatever entries I'd contribute couldn't be fully-rounded pieces.
Are you interested in little teeny entries to "get the ball rolling" on certain subjects...i.e., one may not know all details of someone's bio, but could write a sentence or two...is that enough better than nothing?
Certainly the idea is for others to help add to existing entries to bring incomplete entries up to speed (the "bar magic" section for example, was very brief, & I fleshed that area out a little bit), so are bits and pieces desirable as well as longer, more thorough items?
--I have been tempted to do "bios" for a couple of my favorite guys who are almost forgotten nowdays, but have not felt that the very few "specific biographical facts" I know about them was enough to warrant an entry.
I could certainly start entries on a number of subjects if very brief snippets are o.k.