Hi,and welcome to the site.
To wire the K20 into your crx,you will need to know the pinout of the ecu "E" plug and the k20 harness "c101" plug.The other two ECU "a" and "b" plugs shouldnt need to be touched at all to put the engine into any vehicle.
The only decent diagram online is located here.
http://www.hondata.com/images/k20awiring.gif
That diagram was used on an EG with Hondata K-pro...wiring will be slightly different if using the JDM ecu.
If you need anymore help with what wires go where on the crx chassis wiring,or just cant figure some part of it out,feel free to post the question or pm me or TeamPacman.
Good Luck!