Hellobee Boards

Oliver and S is well known for having very well written patterns. You could start with their Lazy Days skirt to get going: http://oliverands.com/blog/2008/08/lazy-days-skirt-free-pattern.html They also have a free pattern for a pillowcase style dress and a ruffled top.

Figgy's Patterns has this dress which should be very simple: http://figgyspatterns.com/patterns/ofelia/

I like Made by Rae's work too, she has this rainbow dress pattern: http://www.made-by-rae.com/2011/08/rainbow-dress-tutorial/

There are some good options here too: http://sewmamasew.com/blog2/category/kids-clothes-month/

I feel like often tutorials are easier to start with over patterns because they come with lots of pictures and often have a bit more room for error. Small pattern companies seem to do directions better than the big ones. You can also try sewing books like Anna Maria Horner's Handmade Beginnings or Sew Liberated's books both of which have some patterns for clothes among other things.

Craftsy has a class on a romper for girls: http://www.craftsy.com/class/kids-romper-revamp-creative-pattern-adapting/100

I have found some cute patterns and tutorials on this site.
http://www.sewcanshe.com/kidlove/

Etsy is my go to place for patterns. Most PDF patterns sold come with a complete tutorial.