A Google Groups thread has a fairly simple but educational FAQ on how the "Set Crawl Rate" feature works in Google Webmaster Tools.
In short, you can only set the crawl rate for a site on the domain or subdomain level. If you have folders and want to control the crawl rate for items within the folder, you are out of luck.
Googler, Susan Moskwa, said:
The crawl rate tool is only available for sites at the domain or subdomain level; since your site is in a subfolder (/lcsworks), the tool is unavailable for that particular site. If you can verify freewebs.com or a subdomain of freewebs.com, you'll be able to set the crawl rate for one of those sites.
What is the Google Crawl Rate feature? You can learn more about it over here and here. Here is a snap shot of the page, that you can get to by clicking on "tools" and then clicking on "Set crawl rate."
Forum discussion at Google Groups.
