JPG or NEF which is better?

I'm using d90 nikon
i'm a beginner as well
i'm really confused

JPEG is more compatable and is ready to print. Also smaller files. Brilliant if you nail the shot first time everytime, with correct colour balance, sharpening settings, lens correction settings etc.

NEFs require an extra stage of processing by your computer which lets you correct sharpening, lets you correct colour balance, lets you adjust for lens aberations before saving or printing.

It also lets you do it in a non-destructive way, as your NEF file remains intact.

When you fix a JPEG and resave it, everytime you are chucking some more info away, until the point where compression becomes a problem, glorious blue skies have pixelated banding, objects have mushy compressed halos.

The way some pros prefer to work is to shoot NEF & JPEG at the same time. If your jpeg is fine, then great, use it and chuck away the NEF. If the cameras own processing hasn't made the most of the image then go to the NEF and see what you can do with it.

A lot of pros shoot JPEG only for speed and let their picture editor deal with flaws, others prefer the flexibility of shooting NEF.

Your call really.