Toyota Repair: Thermostat repair, thermostat repair, radiator hose

Question
Yea I have a 1995 Toyota 4-runner. Today when I started it up the heater would only blow cold  air and the temprature gauge was reading normal. I continued to drive thinking it just needed to warm up. I stop at two or three lights on the way to the gas station which is approximatley 5 or less from my home. At each stop the tempurature guge continued to gradually climb an still no hot air.I went inside purchased what I need to perchased and got back in the 4-runner. This time though when I started it there was warm air starting to blow but the guage still was now in the red or overheating part of the tempurature guage. I drove strait home and haven't driven it since. What do you think the problem or problems may be? How do I go about repairing it myself?  I think its either the thermostat sticking open or staying shut

Answer
Try replacing the thermostat first, it's located on the front of the engine on the right side(standing in front) it's inside the thermostat housing, locate the bottom radiator hose and follow it up to the housing, remove the three 12mm bolts to remove the housing, make sure you drain the coolant first, the thermostat can then be removed and replaced.