I've heard many things about freemasonry. Some good, many bad. I just want a clearer understanding of what it actually is.

Freemasonry was a social and political brotherhood with many secret rights and ceremonies that started with membership extending only to masons and stonecutters in Europe. It eventually expanded to any men of social class. When wealthy citizens immigrated to the British colonies Freemasonry spread with them. By the time of the American Revolution many of Americas leading citizens and revolutionaries were freemasons. Freemasonry later fell out of favor when a mason who threatened to publish the Masonic secret rights was kidnapped. This caused the formation of the Anti-Masonic party that became one of the most powerful political parties in the United States.

And what was the anti-masonic party (Dem, Rep)?

It was a separate, independent party. It was founded in 1827 and survived until 1834 when many of the members switched to the democratic or Whig (precursor to republican) parties.

http://www.co-masonry.org/language/english/overview/

This particular link gives a very basic overview of Freemasonry and its purposes. It has a lot of other links, depending on your interest.

There are other websites that describe Freemasonry as sinister, and that it is paving the way for the advent of the Antichrist. They're mixed in with the official websites.

You'll have some fun figuring out what you think the truth really is. I suspect it's somewhere between the official websites and the more inflammatory ones.

My dad was a Shriner. I converted to Roman Catholicism several years after he died. We did not always see things eye to eye, obviously. But I don't think that Freemasonry made him good or bad.