Thank you for the compliment, Flickr is a good site to share photos on, along with the Nikonians. I have met a lot of good friends there.
>One last question if you have time. When pressing the shutter half way down, I need keep it compressed to that point to keep the focus locked? Or, if I press it half >way down and release it locks until I finally take the photo.
You must keep it compressed until you take the photo. If you release it, it will refocus on something else when you snap the shot. If you are only taking one shot holding it down will work fine. If you want to take multiple shots or using a tripod (your tripod is your best friend) use the switch.
Back in the old days, the prime lens were marked with the hyperfocal scale and it was very easy to set it up.
Jerry Jaynes Great Smoky Mountains of North Carolina