I have gotten those small wooden cars, trucks ad airplanes at Walmart in the craft section for my grandsons to paint. They are only like 89 cents I think. Hope you get some great ideas, I could use them also!
Cheri

Sand art where they put the colored sand into a bottle and use a stick to make designs. Our five year old grandson had a good time doing this. I didn't buy the kit, I bought a small funnel so that the sand would go into the bottle...I bought the colored sand at Wal-Mart and also glass bottles...then I sealed the top with a silicone glue when he was done. He made them for his other grandparents, parents and I have one on my desk. You can get plastic bottles also, but these glass ones were really neat.

The plastic "bead things" that you put onto a form and then iron them so that they meld together is another good one. I found some of the beads that were larger and easier for a small boy to handle. But..I bought them in a kit and couldn't find them again anywhere. If you have access to a Hobby Lobby or Michaels, they "might" have the larger ones. I think a five year old could do the smaller ones, though...especially with one of the simple patterns.

A variation on Maybee's suggestion of colored sand art...

Color plain white table sugar* and have him make his "sugar art" in little clear bottles. These can be gifts, too, to use in tea, coffee, etc.

If he includes a layer of cinnamon, the "art" and done in a little jar with a shaker top, it will be the makings of "cinnamon toast"!

* For richest colors (deepest, clearest) use the paste-type colors instead of the usual liquid food colors. You can get the paste colors at some groceries, but I always find them in the cake decorating area of WalMart (in the crafts rows). Each little container costs about a dollar, but the colors are extremely intense!

Just put some sugar into a ziplock baggie, dig a bit of color out of the container with a toothpick and dab the color inside the bag. Seal. Then your son will have fun squeezing the color into the sugar. Make a baggie of each color he wants to use.

We've done the "sugar art" with and without cinnamon. We handed these out at Christmas as gifts from the kids. I printed up some instructions for cinnamon toast on the computer and cut them out and had the kids glue them to fancy scrapbook paper. I punched a hole and tied them to the jar with ribbon. My fil is in a nursing home. I have the kids make him the big sugar shakers full of colored sugar for his coffee. It's a great conversation piece for the grandpa and the nurses. For those who can't use sugar, you can always use salt.

For anyone else looking for an idea, I see the Christmas ornament kits at Wal-Mart with the wire and beads. I make my own icicle ornament project by buying the packages of straight floral wire and cutting into halves or sometimes even shorter pieces. I turn over the bottom 1/4" of the wire and let the kids string on the clear acrylic tri-beads, regular facited (sp?) clear beads, and small round silver beads. When the kids get finished stringing beads, I turn over the top 1/4" wire. I tie some embroidery thread or fishing line through the top loop to hang on the tree. It's very pretty and simple.

Another thing I make with my boys that would make a great craft kit is danglers. I've gotten the original idea for this off of the garden junk forum I think. I wrap floral or copper wire around pretty marbles and leave a loop of wire at each end so I can attach some fishing line. I take a wire wrapped marble and attach a needle threaded with fishing line to the end. I give the boys a big bowl of colored beads and let them string them on in any manner that they like. When they get finished, I tie off the fishing line to another wire wrapped marbled. I tie a piece of fishing line to one of the marbles for hanging. We may tie a large bead to the end of the other bead to finish it off.

If anyone else has ideas, please post them. Boys get left out when it comes to a variety in cute clothes and crafts.

These aren't kits, just some Halloween craft ideas that we have used at preschool. Also, both boys and girls like to do simple sewing projects. We make sinple shapes (snowman, heart, etc.) from felt, let the kids sew the around the edge with a whipstitch and stick in some stuffing before it's all sewn, then decorate as desired. They are really proud that they have "sewn".

Glue Ghosts

Squeeze a blob of white glue onto a piece of waxed paper. Dry overnight, and then have the child add facial features. Place on a string and you have a spooky ghost necklace.

Paper Bag Pumpkins

Materials:
Lunch size paper bags Orange paint Green paint Newspaper String

Directions:

Have the children crumple up newspaper and stuff their paper bags so they are full. Twist the unstuffed part of the bag and tie at the bottom to make a stem. Let the children paint their pumpkins. When they are dry, the children can draw faces on them.

Cheese Cloth Ghosts
Materials:

Cheese cloth
2 cups white glue
16-oz. plastic cups

Directions:

Dilute the white glue with 1/3 -1/2 cups of water. Let the children dip a piece of cheesecloth into the diluted glue. Have the children drape the wet cheesecloth over the 16 oz. cups. Let the "ghosts" dry for two days. Carefully remove the cup from the hardened cheesecloth. Let the children glue on wiggly eyes.