I'm assuming you want to get them published.
Two ways to go:
Self publishing:
Have a look at www.Lulu.com - they print individual or short runs and you retail them yourself.
You could set up an amazon / ebay shop and then use a blog/twitter to promote your shop.
Use a publishing house:
Send your manuscripts to known publishing houses to get them to publish it.
You will need to find their submissions pages for guidelines.
Depending on the age range they are for I would try and get an illustrator for them.
I have a friend that illustrates children's books and she said publishers wont look at a manuscript unless there are illustrations too.
Try looking for a local artist that does children's portraits, or look in local art galleries / art cafes to find someone.
Hope that helps