How to run OSX in virtual box in windows 7

This weekend I am getting my new pc. Its specs are as follows:

-Intel i7 2600k 3.4 ghz
-4gb ddr3 1333mhz ram
-512mb gpu until I can afford better
-500gb wd black caviar 3.5' hd


One night, while youtube surfing I came across a video about a program called virtual box. The guy was running xp windowed in this program on windows 7, but it was able to do many operating systems. I would like to put OSX onto my windows 7, but I have some questions (My poor google skills have yielded no useful results)

-Is virtual box the only program I will need? Is it even the right one?
-What will I need OS wise? Will I need a .iso of OSX? the cd?
-What should I assign to the virtual pc? e.g 2gb ram, hard drive space as required, etc.
-I head there are issues such as sound either not working or only coming out of one speaker, is this to do with obvious problems with running one OS inside another? And what might these issues be?
-Can anyone provide a good "walkthough" to set up and install OSX into virtual box?
-Is it "wise" to do this or will it cause problems, I will dual boot if I absolutely have to but I really, really, really would rather not

Any help greatly appreciated,
Tom