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.
Try to choose solar panels that can have their angles adjusted easily. The angle at which the sun hits the Earth changes throughout the year. This means that the best angle to catch the suns rays can be very different between summer and winter. Ideally you want to at least be able to adjust the angle of your panels twice a year, however if you can find some that allow adjustments four times a year (spring, summer, fall, winter) that is even better.
One of the major benefits of solar energy is that it is renewable. The sun (generally) shines each and every day, and there is no reason to worry that drawing power from the sun will somehow render it unusable in the future. Using solar energy, therefore, is a safe and reliable way to power the Earth.