Google Image Search

Google Image Search Questions

How do I rank higher for Google Image searches?
If I block images with .htaccess, will Google still index them?
Will Google index images from pages blocked by robots.txt or NOINDEX?
Is using bigger images better?
If I use a thumb and link directly to a JPG, is that better than trying to get a huge pic embedded on an HTML page indexed?
Will Capital Letters in filenames work?
Underscores or dashes in filenames?
How much alt text is too much?
How effective is listing JPG files in sitemaps?