Philip,
Thank you for your business first of all. Let me see if I can help with your image sizing.
Logo: For best results, you’ll want to set your image to be around 90 to 100 pixels tall. If you need more space for your logo, let me know and I’ll be happy to help you add some more room for it.
Slides: For the slideshow, your images will need to be 670 pixels wide by 350 pixels tall. WordPress will size these down, but it will not scale them up if the source image is smaller than that. You’ll probably get the best results if you create the images to be that size. WordPress actually has some image editing built into its media section. If you’ll select an image in the Media Library and then choose edit image, you can crop and make other small adjustments there.
If you have any trouble, let me know and I’ll be glad to help.
Enjoy your week,
Bill Robbins