Carefully consider the types of solar panels you plan on having installed. Long ago, if you didn't have enough roof space, you'd need very expensive high efficiency mono-crystalline panels. There are now more advanced polycrystalline panels and even thin film panels. If you've got enough roof space, you might wish to look at the size of the panels in relation to their output capacity to avoid having insufficient panels that you need more of later.
It is a good idea to tie your solar panels system back into the grid. With this type of system, you can sell excess energy to your power company. This will help pay for the installation of your system and even allow you to make a profit on your wise investment.