Ace Hobby has a full line of quick building "simple flier" kits that could be a good project for you. Something in a trainer configuration would be easy to assemble and relatively easy to fly:

http://www.acehobby.com/ace/ACE4245.htm

http://www.acehobby.com/ace/ACE4246.htm

You can find the Ace Hobby Simple Series kits at http://www.thundertiger4u.com or at http://www.infinitehobbies.com. I have purchased from both places and have no hesitation recommending either.

My first pick would be the Whizzard since it has tail-dragger landing gear. It will be much easier to take off and land in the grass. The Alpha would be fun to fly from a paved runway if you have one available.