How to connect power inverter to standard lighting circuit
Note that these days the best answer for solar, if you aren't determined to go completely off-grid and if your electric company supports it, may be to get inverters that support line synchronization and ask the electric company to set you up for net metering. 

In this setup the inverters and line feed the house in parallel. If you're producing less power than you need, you buy the remainder from the power company; if you're producing more than you need, you sell the excess back to the power company. Much simpler than trying to maintain local batteries for extra or nighttime power, ensures that all power generated deducts from your electric costs, and in some cases you may be able to sell carbon-reduction credits as well.

I've been quite happy with this setup. I have a relatively small solar setup (8 "standard" panels), but my electricity use is relatively low too, and in the summer I usually do have one or two months of negative net usage. I haven't yet gone negative enough to actually have a negative bill, due to the utility's $6 account fee, but I've come close.

Note: The one disadvantage of a newer metering system is that, to keep your system from electrocuting linemen who expected a cable to be unpowered, net-metering systems are designed explicitly not to run in "island mode"; if the network goes dead, they shut down for safety. That does mean you have to make other plans for dealing with blackouts. As I said, if being able to go completely off-grid is important to you this may not be the best solution. 

If it sounds interesting, ask your solar supplier/contractor for details. Anyone competent should be able to explain it in detail, and run numbers to tell you how long it would take for the system to pay back it's purchase cost after figuring in any currently available rebates and carbon credits (though the latter will be a best-guess, since these are sold via an auction mechanism and prices may change depending on supply and demand).