Why should I use the lens hood?

Is basic terms, when is the best situation to use my lens hood for my Nikkor 50mm f/1.8 G?

What is best for portrait 50mm 1.8G or 1.4G?

I'm really confused of whether I should get a Nikkor 50mm 1.8G or 1.4G, the difference in price is huge, and I want to know does the 1.4 worth this price difference? I was going to get the 1.8 but I heard that the 1.4 is much better, is that true?
I'm getting the lens for portrait photography mainly ( including wedding photography ) .

also, is there's difference in Low Light Performance between the two of them?

Added (1). I forgot to mention that I'm a beginner, I'm amateur photographer.

Why is DigitalRev biased towards Canon?

Just a tongue-in-cheek question really!

I've noticed that on DigitalRev's homepage, all three featured cameras are constantly Canons (the 5D MkIII, 650D and 600D at the time of writing this). Plus, all five cameras in the "5 best-selling cameras" feature box are Canons, 4/5 of the "most wished for" lenses are Canons and all five cameras recommended to me are… You guessed it: Canons! I bought A Nikon 7000 body and two Nikkor lenses, so the last one really doesn't make any sense at all!

I'm not losing any sleep over this, but it does amuse me slightly. My only guess would be that they're sponsored?

Added (1). By the way, this wasn't a "I thought Nikon were better than Canon" question. A lot of people here are saying that both brands are as good as each other and it's down to personal opinion. I get that. The question was just to ponder why the site seems biased towards a particular brand, that's all.

Fast focusing Nikkor AF-S lenses?

What are some fast focusing Nikkor AF-S lenses?

Are Tamron lenses better than Nikon's?

Or at least the 70-300 VC. I went to camera shop to ask about lenses and everything to get a sense of what I needed to start saving, and I originally asked for Nikon lenses, but the clerk steered me toward Tamron. I don't doubt the Tamron I'm speaking of is a good lens- I tried it out myself and he showed me shots from a promotional book taken with it - but he said Tamron is better and mentioned how they've been in business for quite some time. I've always been under the impression you should get lens from Nikon or Canon and I was surprised he started to try to sell me this. Just want info from more photographers.

Added (1). Yeah, I'd like to add when he started talking about how old Tamron was my first thought was "Nikon's a really old company, too."

Nikkor 35mm f/1.8G or the Nikkor 50mm f/1.8G?

Which has better build quality? That's all I want to know, because I'm getting the one that fits my needs, not the better performer. Specs say the 35mm is little heavier (200g), so I assume it has a slightly better built, but while watching reviews, many say the 50mm feels a little better built. Can someone who HAS them or HAS HAD them answer? I appreciate it.

What is the optical zoom of the DSLR I'm interested in?

I'm interested in buying a DSLR lens before Christmas and came across the "18-55mm f/3.5-5.6 AF-S DX VR Nikkor Zoom Lens". Now no matter how hard I look there's absolutely no mention anywhere on the web of how far it can optical zoom. Why can't they simply specify how much it needs to zoom and how can I calculate how much a lens could zoom in the future. All help appreciated.

Would any lens hood from a 52mm filter size work on my nikkor 35mm f/1.8G?

I'm obviously not refering to a canon lens hood, but from nikon. If any lens hood is a 52mm thread, will it fit? The hood (HB-46) that came with my lens broke and I'm looking for a metal one.

Tamron 28-75 2.8 vs sigma 24-70 2.8?

The 28-70 is a bit cheaper, but what's the difference, I have heard great things about both
The Nikon 24-70 is out of my range.

Setting aperture on Nikon D lenses?

I want to know what will happen if I set focal length 70mm and aperture 3.3 on a Nikkor 35-70mm f3.3-4.5 lens. Second question is how to set aperture on a D lens while using a digital camera.