I'm a noob, so be gentle with me.
As a lot of people prefer Crashtest's screenshots over other screenshot packages I went looking for a complete collection and found it at
http://www.mamechannel.it/pages/crashtest.phpHowever, the way these packages are organized, they are a b.... to organize. Here's what worked for me:
Download and install ClrMamePro from
http://www.clrmame.com/download.htmThen extract the dat file from the latest package (at the time of writing that would be the CTMame102.dat from the CTMame102_2.zip file) to your desktop. Then start ClrMamePro. Press the AddDatFile button and point to the dat file you unzipped to the desktop. Just press OK when asked where to put the dat file. In the >Profiler< window you should now see a folder saying Not Used/New DatFiles. Click on this folder and then click on the Mame Shots Collection document that shows up in the right hand window. Now click on Load/Update and select the Default setting in the window that opens. Now click on the Settings button and select the folder with all you zipped Crashtest packages as your rom path and click on OK. Now select the Rebuilder icon. Point the source folder to all your zipped Crashtest packs and set the destination folder to your liking - however, it should be an empty directory. Now click on Rebuild and watch the magic unfold. At least I ended up with what I believe is a complete collection of snaps, titles etc. that I can use as I please. I think Mamewah needs unzipped snaps so just unzip the final snap.zip that you end up with for use with Mamewah.
Hope this is of some use to noobs like myself. Commets or corrections are of course welcome.