I have found it easier, and much faster to use a sitemap program rather than to wait for Google to create a sitemap of your site. Pretty much, you just sit back, while the program trolls through your site under your own permissions. Now, the one that I have used (I think it is the one below), allows you to set words/scripts NOT to crawl. Depending on exactly how many images you have and internet speed, it may take up to a couple of hours to properly scroll through your site.
The programs create exportable sitemap files that you are then able to upload to your root directory, and then point google to it. Personally, I know that I had Google index 9,000 pages thanks to one of the sitemap programs.
This is one, but not sure if this is the one I used. I don't think there are any restricted permissions for the trial, since I only used it during the trial...
http://download.cnet.com/A1-Sitemap-Generator/3000-10248_4-10496253.html?tag=mncolBUT REMEMBER: Search through the features of sitemap programs allowing you to omit certain words like "admin, lightbox, edit, delete, etc"... which ever words or pages you do not want to be indexed. Also, keep in mind that doing so drastically cuts down on the time consumed when it scrolls your site. Finally, the more you restrict from the robot of these programs, the less amount of bandwidth it will obviously use up when scrolling.
EDIT: Forgot to mention the most important part... LOGOUT of your site (especially if under admin) when these programs are running. This will stop the program from scrolling admin or member actions that could be a security risk!