A/c work should be left to a professional, there's alot of things you need to know that experience will teach you more than anything else. Like for instance, I've tried a couple times to convert the civic's with the small rad. on one side and the small condensor on the other side to r134a. No matter what I did it didn't work right. The original r12 condensor is too small to be effective with r134a.

You don't know even what's in your system, you would be best to take the car to a shop and pay them to convert it. You've done all the hard work already, we sometimes at my dealership will charge one up for and we charge one hour.