Hello and thank you! I agree with your thoughts on growing your own food to protect yourself from potential shocks. In a lot of ways I view the food I grow as another source of income - but one that is much harder to lose if the economy goes through a collapse. If I can get debt free and grow most of my own food then I don't need a lot of money.

As far as growing food on a windowsill... I would recommend starting with herbs assuming you cook enough to make fresh herbs worthwhile. As long as the window gets some sun the herbs should do okay. It would be a good place to start. I did a quick google search and this site has some good information on growing herbs on a window sill.

Another option would be to see if there are any community gardens in your area that you could volunteer at. I have volunteered at some in the past and they are a great way to garden when you don't have much room.

Hope that helps!