I recieved my first DIY yesterday. Actually I got five of them. Three of them are my girlfriends. I got a megaminx too. ANYWAY!
When I first looked at all those little bags with dissasembled cubes I have to admit I was a little over zealous in how easy it would be to put them together. If you are just putting them together the best advice I can offer is just to be PATIENT! I got way to excited and put mine together quickly. It was REALLY tight and I wound up having to pop those pains called center caps off and put them BACK in...which is a pain.
When adjusting the tention, which is the hardest part, just look at how far your screws are in on each side. Counting the threads is a pretty good way to gauge. put the cube together and look at it. Look for sides that are squeezing out or sides that are too loose. It's simple if you just give it a little thought and some patients.
Once your done man those cubes are amazing! I love them.