when i've cooked my own food for the boys i puree it, put it in the pots and wait for it to cool before i freeze it.
when i want to use it i take it out, either leave it in the fridge to defrost (took ages though), or i put it in the microwave and heated it up really really hot and then waited for it to cool down before i fed it them.
you need to heat it after it's been frozen.
you should check out anabel karmel's books. she has done loads and they are brilliant!
full of recipes, and it tells you when you can introduce different foods and what to do if baby doesnt like the taste of something how you can incorperate it into another meal to mask the taste but still get the goodness from the food!!!
i have lots of her books for the first stage of weaning. im sure if you look in your library you would be able to get a copy to look through, or maybe she has a website?