There is no formula on what to take, which should be background and so forth, that is why design is an art.
Normally I'll do a lot of tryouts with the set of colours I have, for example which font color looks better at which background.
There is though a rule of thumb, which is to contrast the colours used, most people will say this is common sense, such as light colour font with a dark colour background. Then it may arise, how do you determine the colour for sub-components, such as alert boxes, navigation and so on.
As I see it, you should have your bare structure for website ready, then after that you will need to determine which are your main content, how you want to present it. Maybe a softer colour on subcomponents, which does not need immediate attention.
How do you know whether it's good or not? Easy, as soon as you say "This is nice", that is when it's good. It always help to get second oppinion from other people.
All in all, keep trying with the colour combination, don't stick to only one, and you might be surprised of the composition you might achieved at the end.
@Color Combination: The combination provided by the website is good enough to start with.