We started this outdoor deck project with 44 skids of size 770 x 770 as a base and the garden bed surround. We laid out and leveled on to a base of gravel. I used three 3M hardwood sleepers pinned in around the edge to hold them all together.
I then split 17 normal sized pallets into boards and plinths using the boards from the top and bottom and laid them out in a diagonal pattern across the top.
Then, I covered the whole thing with aqua deck sealer and built the planter boxes out of the larger support boards from the pallets. All up, it took me (working alone) 4 weekends spread out over 3 months. The longest time was sanding all the boards as I only had a hand sander. Oh, and I cut every board with a handsaw.
I was really impressed with how it turned out and the whole thing cost me about $300.
Read Outdoor Deck & Planter Boxes from 94 Wood Pallets! by joyson on 1001 Pallets!