Completely agree with this, you have got to have a thermometer to make a decent roast.
Here is one at target for $20, they should have it in store.
http://www.target.com/Gourmet-Stainless-Steel-Thermometer-Probe/dp/B001GD1WHU/sr=1-2/qid=1247241313/ref=sr_1_2/191-1326701-9082969?ie=UTF8&search-alias=tgt-index&frombrowse=0&index=target&rh=k%3Aprobe%20thermometer&page=1Starting with the oven hot will brown the outside of the meat, creating yummy flavors, but the center will be raw when the outside is cooked if you try to cook it through that hot, so lowering the heat lets it cook through slower without overcooking the outside.
The probe should go in so the tip is right in the center of the thickest part of the roast, that will be the coldest spot.
Preheat to 500, drop to 450 when you put the roast in, after 10 min drop the oven thermostat to 350 and set the probe for 125. When that beeps, turn off the oven, pull the roast out, and let it sit on the stove top covered with foil. The temperature on the probe will keep going up to about 135 over the 15-20 min while the meat rests. When you cut it, it should be medium rare.
If you want it medium, set the probe for 130 and pull from the oven at that temperature, it should coast up to medium doneness as it rests.
The recipe Jenni found looks really good to me.. You should have a roasting pan that is at least 2-3 inches on every side around the roast, and either a rack that goes in the pan to hold the meat up a bit, or you can put the meat on a bed of cut up potatoes (the waxy kind, like red potatoes) carrots, onions (quartered).
The meat and veggies will add their flavors to each other, and then you could eat the vegetables you cooked on as a side, though they will be kind of overcooked.