First of all you have to realize that your cam has a stereo mini plug. Any input other than a stereo mini will cause some problems which may or may not be important - like recording on one channel only.
The best thing to do is to invest in a mic adaptor like Beachtek which allows you to input one or two mini plugs or XLR fittings. You can then choose stereo or mono, line or mic, etc.
As far as actual mics go, do some internet searching for microphones. Most all manufactures have a list of what mics are best for certain situations. A quick and most viable approach is to go to a local music store (not a photo shop) that sells mics and such to bands. You can get a personal recommendation and can probably exchange your purchase if not satisfied.
Online purchases are great IF you already know what you need. Azden has a whole line of mics geared to videography. They are not "pro" but good enough. I have their wireless system and use Sure mics and an Azden shotgun.
Only you can figure out exactly what mics are right for you at the price you can afford. And we haven't even started on the subject of mixing.
Videomaker Magazine has an article every month on sound recording. I suggest you start reading them.
Most important (just as in video) is the technique that you use rather than the equipment.