thanks for posting this Stacey - just about to start advertising one of ours!! I was thinking the usual routes of Horsequest, Adhorse and Horsemart as well as other free ad sites (seeing as they're free!) but to be honest I am not hugely hopeful at the moment with the financial climate the way it is!
Become a member of Zangersheide and advertise your foals in the Z magazine for free!!!!!!!!!!!!!!!!!!!!!! 20,000 people read that magazine around the world every two months.
It's only 50 per year to be a member of Z, which I believe is less than advertising in most magazines.
i find horsemart not very good simply because the time you have put yr horse on there its drop so many pages in a day and if anyones like me i only look at the new first couple of pages each day if you are a new user and dont search fully you can easily miss a advert? i think horse deals is prob the best especially when they have a youngstock~broodmare feature on or horse quest or as Ken says Z.