I am always use this tool to find online directories: http://soloseo.com/tools/linkSearch.html...
Submit a website in directories that's really a good idea because it become helpful a lot to website for good ranking and traffic. Submit a website in proper way and right website niche directories which have a good value . PPdirectory.com is one of the best website directory to submit website.
Most web site directories have little search ranking value, there are a handful of paid directories who's content the search engines respect, along with the tough to get into DMOZ.org human edited directory.
The general rule applies: the easier a link is to get the less valuable it will be, there are tools and services that bulk submit to multiple directories, diluting their value.
If you had a link from a high raking off short directory it would still be of some search rank benefit.
Jake is correct about a handful of paid directories that are important. The rest are not worth your time.
Also look for where your target market is. If you can list your company in a directory that is read by your target market it's a win win. I included two sample below that let companies list in their directory.
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i agree with jake.
Okay I have a website indexed by google and all other search engines, is it a good idea to submit it to some free directories? the website is located in US and for US consumers only, but is it okay to submit in some directories located outside US? or it is just not relevant? maybe some Spanish directories etc... and what are other ways to get backlinks, I know only relevant to field is good. Any suggestions?