Here are some inspirational images for what to wear. Also check out:
- Kids: http://www.mcpactions.com/blog/2010/05/25/what-to-wear-kids/
- Babies: http://www.mcpactions.com/blog/2010/04/27/what-to-wear-2/
- Couples: http://www.mcpactions.com/blog/2010/06/22/what-to-wear-how-to-dress-for-engagement-pictures/
There are lots of ideas here too. For girls I suggest going for a look...think Boho, hippie etc.. for boys think rock star, rugged etc..