There are many different kinds of solar-panels. In general one can differentiate between:

Anamorphic, Polycrystalline and Monocrystalline

All will get you electricity strait from the sun. They do differ however in some ways.
First of all in Price. In general, the anamorphic panels are cheaper, also they normally come with less power output per square meter.
So, for a 10 watt panel, you have about 30% more panel then if you have the 10 watts in polycrystalline but you also paid less. They also have the advantage, that they produce usable currents even at not too favorable conditions, especially when its cloudy. On a strictly watts or amperes for euro/dollar the anamorphic panels are great if you got space, a lot of it.
You can identify them by a dark even color. They are normally found where ever there is very little electricity needed like calculators,solar lights or similar small appliances.
In larger installations, you normally find the more expensive but also much more efficient polycrystalline panels. They are the type you see when solar-panels are used to produce any kind of "serious" electricity. They glow with a characteristic blue shine and are always a collection of interconnected cells, normally 32 or 36 cells. These will produce about 20V and with that charge 12V systems. Any solar-panel can be wired to others to double the voltage (for 24V,36V or 48V systems) or to increase the ampere output (2 panels of 5A can become 1 of 10A) in just the same way as this is possible with batteries. Modern panels have build in diodes so the electricity is sure to flow only in to the batteries, not the other way around.
The problem with the polycrystalline is, besides the price, that they need real sunshine to work. Also one should orientate them well towards the sun, preferably moving (automatic or manual) them periodically with the sun (up to 30%!!!! more yield) and make sure that no part is ever covered by a shadow of even a piece of grass or a leave. A big panel with 100 watts or 8A output goes down to a few milli amps if only a corner of it is covered. There are some panels that are protected about this with build in diodes between every cell but they are rare and very expensive.

The last category are monocristalline panels. They are the most efficient and the most expensive panels you can buy. They also are interconnected cells and shine blue but do not have the "chipped" look of the polycrystalline cells but are made out of one piece.

So it depends a bit on what you want to do. If money is a problem, you get great deals on the anamorphic panels, but you have to have the space,a lot of space, to put them somewhere. How much space? Well, lets see how these panels work:

The sun beams about 1000 watts of power every hour it shines on every square meter on the planet. Thats a lot of power, easily enough to power basically everything we need. Unfortunately, we can not convert this power to 100% in to electricity. The best solar panels in existence manage about 24% and they normally hang around somewhere in space or are used by similar companies that can afford them.
The panels we can buy today are more in the neighborhood of 19%-21% for the polycrystalline and anywhere between 9% and 16% for the anamorphic panels. So to get 1000 watts we do need quite a lot more then 1 square meter. You see, size does not matter here, you have to look at the rated power output to calculate how many panels and from what company you need in the space you have.

In case of having a large roof or similar, it is absolutely worth a look in to cheaper anamorphic panels since they also work quite well in cloudy conditions, if you have more of them (for the same money as the polycrystalline) they will actually perform the same, if not better.