Featured item slider is the perfect Slideshow for WordPress. It displays up to 5 Posts or Pages with Title,Description and Image for every Post.
You can Insert the Featured Item Slider almost everywhere you want (it looks best under Navigation Bar)!
You don't have to edit the Stylesheet you can make changes directly in your Administration Panel (Settings --> featured item slider). Here Change the height and width, all the other dimension will be changed automatically. Also you can change the colors.
= What is perfect Resolution for the Images and slider?
Plug-in will be takes care of all the Resolution automatically. so you can use image and slider of any Resolution you want without doing any css fixing.
= Thumbnails are not being generated?
Thumbnails are being automatically generated with WordPress, when you are uploading an image. If you are already having pictures set you have to regenerate thumbnails using the "regenerate thumbnails plugin", otherwise old thumbnails won't display.