It depends on where you are ..........If you are a fresher mention all your skills or talents or knowledge or qualifications whatever you have decently one by one....... If you are working professional make the your carrier achievements so far as an attractive part.
Balaji Varadaraja...
Before starting to pen down the content, try to find a good resume format online and then put on your details in that template... In this way, it will make your life easy and will also give you more content to fill up....
Kaustubh
Since you are fresher you don't need to add all nitty ditty details. Just keep it simple like you are introducing yourself to somebody. Just one page max two. Keep relevant data. If you have some exceptional quality them only mention it. Hope it helps you. Best luck.