Great question! We always need more people doing merges! :)
Merging profiles is pretty easy. One thing to keep in mind on WikiTree is that we always want to merge newer profiles into older ones, and it's best to merge all duplicates into one, rather than, say, merging Rice-2410 into Rice-1299, and then Rice-1299 into Rice-1252, which creates multiple redirects.
All that means is that it's best if you can identify the lowest profile ID at the beginning. Then merge all the others into that one.
Just go here: http://www.wikitree.com/wiki/Special:MergePerson
and put the higher ID in the top field and the lower ID in the bottom field. From there you can merge them, compare them, mark them as unmerged matches (meaning there's more investigation to be done), or mark them as a rejected match.
One more tip: It's easier to start with older ancestors and work your way down, because when you merge two profiles you always have to merge (or at least match) the parents, otherwise someone's tree will get broken.
If you have any questions, don't hesitate to ask!
For more info (in case my answer wasn't long enough, haha): http://www.wikitree.com/wiki/Merging