We built our jumps according to the section in the AKC Obedience regs called "suggested construction of jumps". Here is a link to the regs ( http://www.akc.org/rules/
The only caveat I would share is don't build your broad jump out of wood! We originally built both jumps out of wood. The high jump is still functional after many years of use, but the broad jump quickly became warped.
The solution we came up with was to use vinyl garage trim to construct a broad jump. It looks just like wood, but doesn't warp in damp conditions. The real bonus is that it never needs repainting!
PAM Guardyan's Gavin, VCD2, CDX, RE, AX, AXJ, AXP, AJP, TD
PACH Guardyan's Helki, CDX, PCDX, RA, MXP3, MXPB, MJP3, MJPB, CGCA
Guardyan's Kamikaze BN, CDX, RE, OAP, OJP
Guardyan's Kricket BN, CD, RN, NAP, OJP