Hi Lorri, Put you oven on to 180-200 degrees mark 6, and let it get up to heat. Take your meat and a skillet or other pan/tray that can be used on top of the stove. Heat the skillet up and put 2 tablespoons of oil in the pan when that is medium hot put in your meat. What you are doing now is sealing in all the flavour and juices. Lightly brown your meat all over, and when it is nicely coloured, put it in the oven.
You cook your meat for 'pink' 20 minutes per pound + 20 Minutes " for the oven" this allows for the fluctuation in temperature in differing ovens as some are hotter than others. For Medium to well done give it 25 minute per pound and 25 minutes "for the Oven". This part is VERY important, When your meat comes out of the oven, you must let it rest for half an hour. You can be finishing off the vegetables or gravy at this time. I cannot stress the importance enough to let your meat relax. This allows the juices to reform throughout the meat, finish cooking the meat and it also keeps the joint tender and moist.
If you do not let the meat relax, what happens when you slice/carve(if it was a bird) the meat All the juices escape and you are left with a dried tough joint and a very expensive pot of gravy. It could also still look pink and bloody. Don't worry about your meat getting cold you can cover it with foil or a clean tea towel I find better. and served on hot plate keeps it tender too as it does not get chilled and tense up,You can use the juices at the bottom of the pan for gravy. One final tip, never put salt on a joint before you roast it as salt draws out the moisture in the meat. As you have already salted it I would baste it every 15 minutes instead of every half an hour, if it begins to look a bit dry, add a cup of water to your pan and baste it with that.
I hope this helps. All the best. Rab