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.
For better savings on your utility bill, keep your solar panels clean. Solar panels are practically silent and since you don't touch them, you can easily forget them. The cleaner their glass panels are, the more clear surface area the sun has to "work with." There's no set amount of time that you should clean them. If you live in an area with lots of wind, dust or construction, they may need cleaned frequently. Some ares may require weekly cleanings.