Hey Ben,
Boy there are some great threads and pics about trim tabs on this sight. I myself have never had them on a boat, but there are a bunch of people here that swear by them. Search through the sight. Lots of pictures. To get you started, try looking at this thread.
191FS Trim Tabs Install
Also check that poll on trim tabs. Lots of links and opinions. Basically, putting trim tabs on your 190bay has been done before, and you should be able to get the details. Good luck.
Ron