If you want to exclude all the search engine spiders from your entire domain, you would write just the following into the robots.txt file: 

User-agent: * 
Disallow: / 

If you want to exclude all the spiders from a certain directory within your site, you would write the following: 

User-agent: * 
Disallow: /aboutme/ 

If you want to do this for multiple directories, you add on more Disallow lines: 

User-agent: * 
Disallow: /aboutme/ 
Disallow: /stats/ 

If you want to exclude certain files, then type in the rest of the path to the files you want to exclude: 

User-agent: * 
Disallow: /aboutme/album.html 
Disallow: /stats/refer.htm