[Plugin: Slideshow Gallery] New User Questions

These questions might be a little under everybody’s radar, but I am very new to wordpress and using plug-ins.

I’m processing a lot of photos for a website redesign that I’m helping with and we want to use this plug-in. I am just wondering if someone can confirm the dimensions that images should be input at and if somebody could tell me if I have to cut the thumbnails myself or if the plug-in generates them from the slide images. If I have to cut them (which is just fine and actually what I’m used to) what are the dimensions for those?

I feel like a fish out of water, and I appreciate any help you could offer. Thank you very much!

http://ww.wp.xz.cn/extend/plugins/slideshow-gallery/