Starting with OpenGL

Hi all for the first time.

I’m reading plenty of things about starting with OpenGL (included the wiki mentioned in this forum), but I want a confirmation on what to do to achieve this and be sure i’m not using any not needed libraries or references.

I have a directx game and i want to make it multiplatform capable. I want to start the opengl engine totally from scratch and with latest features-> OpenGL 3.0 etc.

My question is:

What do i have to do (references, downloads and stuff) to get a program that i can compile in linux and in vista and runs an empty opengl window on each?

What will i loose if i use GLUT library? (What i need is performance and total control of features)

Thanks all ^^