Do you use robots.txt file on your web site? I don't have much experience with this. My question is what files and locations should I forbid and to what robots specifically, if any?
You just need to develop your site & your content should be fresh & unique. Then you need to submit your site to major search engine so that Google crawler can crawl your site.
For faster indexing of your site and effective search, you can bookmark your site to certain good social site and submit it in the several directories for getting backlinks. If the sites you submit to are dofollow sites , you invite Robots to crawl your site. as many time your pages are crawled by the bots, it get indexed by the google
Do you have something you want to hide from search engines? If so, you should consider password protecting the information and using the noindex meta tag in addition to a robots.txt file.
Otherwise, there's no reason to use a robots.txt file.
The reason why I asked this is because people are always telling me that certain files are of no use at all for search engines, like JavaScript, CSS, flash, XML. So why not forbid them from the start and avoid their indexing?