This is a place to collect links to good diy guides and antenna manufacturers.
This a link to build instructions for crosshair style 5 - 10 dBi directional antennas. I made some for 2,4 gHz a while back and they work well with OHD.
How to make cloverleaf antennas:
Custom made antennas from germany:
Custom made antennas from poland:
High Quality antennas from the USA: