Replace your thermostat. It is fairly easy to do. I recomend an OEM honda one. I bought a murrays POS one, and the quality was just not there. They cost a little more, but well worth it.
Anyways, you just have to pull the hole, and with extensions, take the two bolts holding the thermostat housing on. If you cant get at the lower/rear bolt, you may find it easier to just unbolt the stater. Then, pry on the thermostat (not on the actual block) and then replace. Make sure you put it in the right way and you line up the two little notches on the gasket to the block (you will see when you do it). Then reinstall everything, then take the cap off the raditor, fill, turn the car on, and keep adding until the lower raditor hose turns hot.
On honda's a thermostat will normally open within 10-15 minutes of just sitting, and maybe a little less when just driving around. If it does not open, then it needs to be replaced.