I buy items like roast on sale. For instance, when other folks are buying steaks and sausages for the BBQ in the summer, roasts are on sale, so are Turkeys and hams. I buy some and freeze them. Steaks and sausages are on sale over the winter holidays... and so are most fish.
I tell you this, because I generally start with a frozen roast.. but you can do the same with fresh.
I start about 9am. We usually eat about 5 or 6pm.
Now most folks thaw out frozen food, I don't. I take off the plastic and such and pop it into the the roasting pan (leave any strings on it though). A slowcooker is even better! It's during the thawing process that food poison happens... so I avoid it.
Fill the pan with water, about 1/2 way. Trust me. Add your favourite seasonings. Clubhouse makes an awesome roasted garlic and pepper that's easy on my stomach and very flavourful. Others use steak spice, onions, garlic, peppers etc. You can add potatoes and carrots if you wish. Not everyone likes them cooked this way. Now cover the rest of the roast, if possible, with water, but allow some room for the water to bubble. Cover.
Bake at 350F (175C) for an hour, then reduce heat to 250F (120C) for the rest of the day. Check occassionally to make sure there's enough water. (If using a slowcooker, just set it to medium and leave it, if you don't have temp gauges).
About the last hour, take the cover off if it isn't browned. The last half hour, increase the temperature again to 350F (175C)... just a safety precaution.
This roast will melt in your mouth and fall apart on your fork. The water is awesome for gravy.
If there's any leftovers ... not likely unless it was a large roast for a small family ... save them for the stew!