THE best advice I can offer is-
Go to
www.groups.yahoo.com/group/altfuelfurnace. If that doesn't work, search in the Yahoo groups for Altfuelfurnace. Very good group, very, very helpful. Don't waste your money on plans. Anything thats in plans is somewhere on the net for free.
Here's my burner setup-
Beckett AFG oil burner off a 50k btu warm air furnace, had a .5 gallon per hour nozzle, with pressure pump (100psi)
I took the original nozzle and pump out, and used a special nozzle. Actually, it wasn't very special; a Reddy heater nozzle for $12. Real waste oil burner nozzles are nearly identical; the reddy nozzles are made by a company that makes real waste oil burner nozzles. The difference is that the reddy nozzles cost like $20 less.
The oil needs to be preheated. For motor oil and hyd. fluid, I think I heat it to like 170 or so degrees F (been a while since I messed with it). Heaters are cartridge style elements. Normally a few bucks a piece, I got a lot of 8 for a buck on eBay. The heaters go in a aluminum block, with holes running through it for air and oil (I'll explain the air). I spent a few hours and just milled a aluminum ingot left over from sand casting into a block with holes for heaters and oil.
The nozzle needs compressed air. I got a compressor for free. Hopefully it lasts.
To fully understand it, check out the altfuelfurnace group I mentioned. Like I said, very helpful. And when it burns right, it doesn't really smell, and doesn't generate smoke. My favorite fuel for it is hydraulic fluid and tranny fluid, since it burns very nice. With some additional parts, ($30) I can burn vegetable oil. My system was done on the cheap, and I don't plan to use it for home heating. I was to use it for making maple syrup. If it were to be in constant use everyday, I'd use some higher quality things that I didn't make.
Now, I'm not liable if you go try it, mess up, injure yourself, or try to put it in your house, and burn your house down.
Pretty cool thing to see, though. I can do an oil change on the four wheeler, and heat with the oil I just took out of it (though I really should filter it better).