I bought two Phillips 150 watt agrilights and wouldn't you know, I fried the plants I put under them the first time. I think I had them much too close. How far should I keep these away from the plants and how long can they stay on?

The standard rule of thumb is if your hand feels hot where your plants are, the lights are too close. It should feel comfortably warm. Also, with a fan, you can get the lights a little closer.

24/0 will generally get you the best vegetative growth. If you're going for flowering/fruiting, that depends on whether it's a short day/long night plant or not.

I think these are incandescent bulbs. Are they sort of bell shaped like a floodlight bulb? Do they screw into a regular fixture?

If the above is true then these are absolutely no good for growing anything despite the claims to the contrary.

The other possibility I found was the Phillips Agro light which is a HID (high intensity discharge) HPS (High Pressure Sodium) lamp. This lamp would need a special ballast and socket and would be a long skinny tube. HPS lamps are great for growing things but you should follow the rule of thumb that karenrei pointed out.

If the lamps are incandescent you should just return them. If you read around these forums, most people use tube florescent lights in $10 shop light fixtures from Home Depot or similar.

Jon