I finally was able to get Jack to nap in his crib, we have a wedge at the top from Babies R Us and the only problem is he starts laying at the top but sort of slides down and ends up on the flatter part and sideways, any suggestions for keeping him up at the raised part of the matress?

Yes, we have that same problem too. There are suggestions on this website under "Treatments" and under "Propping Baby". The towel idea had helped us a lot. Good luck! :)

I have a pillow under one end of Catherine's mattress. I bought the wedge from Babies R Us, but it didn't incline her enough. I have a rolled up blanket placed against the crib bumper, and I put Catherine to be sort of on her side with her back against the rolled up blanket. Then I put a sort of heavy crocheted afghan on her for a cover, and it's heavy enough to help hold her in place. She does scoot down the incline some times but the weight of the blanket keeps her in place most of the time.

There is a nifty way of swaddling your baby and tying it into the sides of the cot so that they don't slide but I don't know how to do it. Also, the SafeTsleep is another option... you can find it on the web. I would try and go for some of the ideas on the treatment section, that Sheila mentioned, first though.

We had that problem too, even fashioned a sling from a receiving blanket that was a real PIA!
I would suggest either a tucker sling(www.tuckersling.com), or the SafeTsleep device(www.Safetsleep.com).
Both have simple ways to elevate a baby that keep their faces clear, and you can get the 30% incline on the mattress that the Pediatricians recommend to help prevent spitting up when the sleep.
A little pricey, but sooooo worth it in the long run.
The tucker sling worked very well for us.

Good Luck,
Lisa