Still confusing about lens! Any suggestions?

Which lens is better in general, Nikon or Canon?
What's the pros and cons?

Depends 100% on the camera… Why use Nikon lens on a Canon camera and vise versa?

You've given us NO idea at All of what your looking for… Portraits? Sports? Landscape? Macro?

And what's your budget?

If you are shooting sports, Nikon AF-S lenses are the fastest at auto-focusing, the Nikon D3 cameras have the lowest noise at high ISO settings

If you are shooting video, only the Nikon D3100 and D7000 can auto-focus in the video mode.

In general, long Canon lenses cost less by about 5% to 10% depending upon the lens.

But really you need to pick a camera system, not a lens or camera.

This can take up to a full year of doing research, rummaging around the Nikon and Canon websites before you will come to any conclusions. Remember, once you choose the system, you will be married to it for a few decades.

First of all, the bleedin'obvious. Nikon fits Nikon, Canon fits Canon. You can fit a nikon on a canon but it requires an adapter or major surgery.

Nikon has a good lineup on the low end with the 18-55, 18-70 and 18-105, all very good. 55-200, 55-300 on the long end. Weak point is the 50mm f1.8 which doesn't autofocus on the low end bodies.

Canon has the only macro lens I know of that does more than live size.MP-E 65mm f/2.8 1-5x Macro Photo and it has a 70-200 f4 which is reasonably price.

High end of the scale there's not much difference. Canon's 100-400 is more affordable than Nikon's superb 200-400. Nikon has their unique 105 and 135mm primes with distortion control

So, advantages and disadvantages there. If you think $600 is a lot of money for a lens then Nikon may be for you.