If all you had encountered so far are “Make money fast”, “$50 to submit to 300000 sites” kind of websites, be pleasantly surprised with selfpromotion.com.
Not only do they provide free services, they ask that you pay only if you find the service useful. That’s a rare and bold claim.
If that is not enough, there are good articles and content on the topic of website promotion. One caveat – the article are pretty dated. Most information are still useful and relevant though.
I have not pay anything, but maybe I will. Need to poke around more into the functions. Give it a try.