Welcome AnotherBob
You'll find that the people here at MobileRead are very helpful and nice.
As you may have noticed there are specific threads to both Kindle and Calibre, so any question you post there will be promptly answered and also you have lots of information already available.
One thing I can suggest is that you check out
Duokan, it's an alternativ firmware for Kindle. It has better support for .pdf and comics/manga, if you're interested in any of those. The risk of installing it is almost null AFAIK and you can always remove it easily.
Hope to see you around here, and if you got nothing to do and just want to have some fun you can always join some game (mostly games of words) or discussion at the Lounge
