Ok, you need to buy a FSM--factory service manual--for your year. You can buy a LICENSED copy on CD for $37 from these guys:
http://www.naxja.org/forum/showthread.php?t=1027854
You can find their products on eBay and save a little.
Please don't buy pirated copies or "aftermarket" manuals.
You can search for the printed FSM on eBay and Craigslist, but they will cost more and you need to make sure you get all of the pieces--the CDs contain everything for one price.
Now, HVAC issues--the blower motor is dead. You can test it, under the hood it is mounted in the firewall, passenger's side. If you have a/c you may have trouble getting to it, but for our purposes right now you simply need to locate the wires running to it. You need a couple of long pieces of wire so you can jump power and ground to the blower motor directly from the battery to see if the blower motor runs.
Next, there is a blower motor resistor pack under the dash, passenger's side. The general issue with the resistor pack is that the resistors for the various low speeds burn out, then you only have the blower on HIGH setting only, and eventually nothing at all. So, after you find out if the motor is even good, then you should check the resistor pack.
Next, the HVAC electrical circuit is weak. What often happens is the connector to the HVAC switch simply melts. You can pick up a connector with about 4-6 inches of harness attached at the salvage yard and solder it in, or buy insulated individual connectors and use them.
The switch itself could be bad.
Do you have a/c? That could have its own problems.
Vacuum is important. There is a vacuum reservoir under the passenger's side of the front bumper--will look like a ball or capsule. The lines running to it like to break under/behind the battery, and when you have no vacuum reserve, when you are under a load/accelerating, the vents will switch to defrost which is the no vacuum default.
Well, hope that gives you some starting points.
Good luck.