Frustrated by the inefficiency of leaker hose, we have, for the past
three years, been relying on a homemade sprinkle irrigation system to
keep our two raised bed veggie gardens going throughout the growing
season. We'll be using the system again this year. A few basic tools
and about 10 bucks for materials at the local hardware store will get
you going.

No plans are needed. Take a look at ours and you'll have no trouble
figuring things out.
http://www.sayokay.com/homemade.htm

To irrigate a standard 4 x 8-foot raised bed, you'll need to purchase
two 10-foot lengths of half-inch PVC pipe, plus four right-angle
couplers, one tee (3-point) coupler and one double-tee (4-point)
coupler. Also, you'll need a 5/64 drill bit to perforate the tubing.
The couplers provide such a snug fit that you won't necessarily need
to buy PVC bonding compound. That way you can knock the assembly apart
for winter storage.

Once you've got the rig assembled, find an old length of garden hose,
chop off the male end and slip the stub over the entry tube. A 50-cent
tightening hose clamp will provide a leakproof connection. There's a
commercial version of this setup that will allow you to thread a stock
=BE-inch hose connector directly onto their system. That sells for
$24.95. Gardeners Supply Company markets something similar that is
suitable for irrigating 3-by-3-foot raised beds, and that's selling
for $16.95.