In my previous basics post, I described the types of dishes I use for freezing. When I freeze things in pyrex bakeware, I sometimes thaw it overnight in the refrigerator the night before baking it. Most of the time, I don't do that, however, because I don't plan ahead or I forget. Often, I just take it right out of the freezer and pop it in the oven. I usually turn on the oven and put it in before the oven is warmed up all the way. I have never broken a dish this way. Pyrex holds up to a lot of mistreatment. A frozen solid casserole type dish in a 6x9 size dish takes about 1 hour and 15 minutes to cook. I cover it with aluminum foil (bend it so it makes a "tent" and does not touch the food) for the first hour and then bake it an additional 15 minutes with the foil removed.
In recipes where I start with pre-cooked chicken, I place the cooked chicken in a glass dish (usually one of those 6x9 glass ones) and microwave it at half power for 3-4 minutes. I take it out and remove hot pieces around the edges and then put back in the still frozen parts in the middle until it's all thawed. I never use plastic dishes in the microwave. Ditto for styrofoam (like the containers that microwave mac and cheese come in, or take out containers when re-heating). Both plastic and styrofoam can release chemicals into food when heated. Eating these chemicals can possibly lead to cancer over time. So I just use glass.
For frozen ground beef, I place it in a quart sized freezer bag and flatten it. I store it flat in the freezer. When I want to use this, I get it out of the freezer and whack it on the counter a few times. The flat piece of ground beef breaks into several pieces and I add it frozen to the pot of whatever I am making. Usually what I am making is something like pasta with tomato sauce or something like that. I drop it into the boiling water with the pasta and it thaws while the pasta cooks. If I make something like shepherd's pie or something that requires mixing the beef with other items, I thaw it in the microwave like I do chicken.
Another reason for using the freezer is that you can buy meat or other stuff while it is on sale. I like to buy pork tenderloin in bulk when it is on sale. For these, I just bring them home, in their plastic vacuum-packed wrappers, and pop them right into my freezer. These are so easy to bake and turn into delicious BBQ and other things.