When thinking of a basic solar power system, think of a small cabin in the woods that needs four 12 volt batteries as a simple example. The assumption being that you are planning to run a small minifridge, a few lights, and a small stove. Perhaps, you may plan on powering a few simple tools as well.
The most basic setup will include a 3 panel (45 watt) solar kit and perhaps a 300 watt inverter at the minimum. This actually is a good starting point for a basic solar power system and then an additional 60 watts can be added. Anywhere you can eliminate the use of an inverter will help cut back on cost and the amount of converted current needed.
Quite simply this means connect the solar panel and the tool directly to the battery using their wires leaving out the inverter. Another simple solution is to wire the solar panel directly onto the tool like a solar panel wired onto an attic fan. In this case, the fan will only run when the sun is shining because there is no battery involved to store charge.
When mounting the panels, be certain to angle the panels slanted about 12 degrees thus maximizing exposure to the sun. If done correctly, then the three panels will yield 15 watts each at midday sun or 1.5 amperes. Keep in mind that a cabin in the woods will have plenty of trees around it to cast a shadow on the solar panels.
Considering the solar panels need sun to generate power, the trees might be a problem. In this scenario, the batteries will be at a trickle charge over the course of the day and will not even be able to power a light bulb.
If using the cabin for intermittent getaways, then perhaps a generator may be sufficient instead of solar panels. If planning on living in the cabin year round then consider a system of 500 watts at a minimum and a 1000 amp hour battery bank so that you can live comfortably inside.
On a more professional level, a basic solar power system includes the solar panels, charge controller, batteries, and an inverter. This will generally include a large array of solar panels that are wired together. In this scenario, the appliances will just be plugged into the inverter as needed. This system is generally installed by the local power company and comes with several rebate and tax incentives.