Can I just use the USB port that came with my camera to transfer pictures from my SDHC card to my computer? Or do I have to buy the memory card reader?
I always prefer to use a card reader when transferring pics to the PC. I usually don't like the software that comes with a camera. When you use a card reader, you can totally bypass the software. I have a universal card reader, so I can get pictures from just about any card or camera. But to answer your question you do not need a card reader but many digital camera people prefer to use one anyway.
Most card readers accept many of the standard memory cards. Just ask the salesperson if the reader you are buying accepts Memory Sticks and SD cards. You never know when you may buy a camera that uses SD cards most do.
You can do that, but if your camera doesn't have enough memory you may only be able to take a few pics. You can by a pretty check SD card and hold a lot of pics. I think you'll be happier that way.
Most cameras work with the USB cable to transfer images and it is not necessary to buy one unless your camera does not support the USB cable(which is unlikely because it came with the camera. I have a memory card reader and I can see a slight increase in the copy speed of the images.
No it is not necessary at all. The USB port connector will work just fine for picture transfer. The advantage of a memory card reader is that you don't use camera battery power. This could become an issue if your batteries were running low and you had a lot of pictures to transfer.