Where can I start to program a S5PV210?
The S5PV210 probably isn't the best chip to learn on for the reasons stevenvh mentions. I would never buy an SBC before I had already downloaded the manual and given it a quick once over. If you're just learning, a chip/platform with an active community is much more important than price.

That being said, the S5PV210 looks to be an ARM Cortex-A8. So maybe maybe, you might be able to get a BeagleBone LED example to work. But this statement comes with absolutely no warranty whatsoever that you will not damage your SBC.

Hopefully the SBC came with schematics and a datasheet for the chip. Read them. Understand them. The following code, read it, understand it. After you feel you understand it all, read it again. You will most likely need to make modifications to make it work.

After you get the code loaded, don't just let it run. Set a breakpoint early on and step through it, making sure everything is behaving as you think it should.

All that being said, have a look at this BeagleBone LED blink example paying special attention to where it states that the Cortex-A8 support is experimental:

http://elinux.org/BeagleBoardOpenOCD#LED_blink_example