Both DigitalPoint.com Forum and The Warrior.com  Forum, have threads where people offer their services for sale. You can post an offer at no cost on Digital Point but you have to have been a member and have 15 posts to your name in order to do so. Warrior Forum also requires that you have been a member for awhile and there is a fee to post a WSO (Warrior Special Offer).  Presently you can have a warrior offer for $20/Thread (that per post of your sales letter).

However, you can still earn money through these boards. Join both of these groups. Scan the posts on the WSO thread and the Buy-Sell-Trade board at Digital Point.
I have consistently made a minimum of $200 from Warrior Special with an unknown website and a new book I created while in a training class with my students.

Offer your services to the people who are asking questions about the services currently offered, or who have said they've bought the service.

Do this by the private message function on both boards, not by posting on the thread.
Other forums where you may find clients.
SitePoint.com
v7n.com
webtalkforum.com/
talkfreelance.com/
associateprograms.com
wickedfire.com/
im4newbies.com/forum/
wahm.com/forum/
internetbasedmoms.com/bb/
businessforum.net/
Place ads on craigslist.com  and usfreeads.com offering your service.

Perfect, Thank you for this info.