Normally any vector graphics are handled in adobe illustrator or another vector based program. Because of that it is nearly impossible to find pre made adobe photoshop vectors.
I recommend getting a cheap copy of illustrator. Go for version 8 or 9. You can find illustrator vectors all over the place, and you can import them into photoshop from illustrator, or you can just use illustrator for your vector graphics.
Istockphoto has a ton of images.
Also, you can import an .eps file into photoshop, but it will be raster zed. Photoshop will prompt you for how large you want to import it as, so make sure it is large enough not to loose any quality if you print it.
To Design logos and Icons play around with shapes in Photoshop. Learn a lot about using Pen tool. Do little bit search in Google for sites that are providing free images. I suggest instead of putting images in Logo try to design a logo with available tools in photoshop.