Can Anybody Help me with Audio Terms?

I am on my way to build 3 way speaker system and this my first time. I heard that i have to make crossover into the speakers which will drive the low frequencies to the woofer and mid ranger whereas the low pitch to the woofer. I went to a site that calculates schematics for any sort of crossovers. But they ask me the several things out of them i understood some of them while others made my mind disrupted. so please state the meaning of the following:
High Xover Frequency ( fh )
Low Xover Frequency ( fl )
Frequency Spread ( fh/fl )   here there were 2 options I.E, 8:3 octaves and 10:3.4 octaves
Bandpass Gain ( g )
Crossover Type
In the last one there were several options:
1st Order normal polarity
2nd order reverse polarity
3rd order reverse polarity
3rd order normal polarity
4th order normal polarity

What are the differences between these crossovers? Which one is the best and why? If nothing is best so what is the difference?
Sorry I am a novice. So guys please be easy on me.... 
Thanks In Advance

framistan4 years ago
I went down that road once. Bought a complex book on how to design speaker enclosures. Tried for weeks and weeks to figure out all the equations. Finally, I just threw the book to the side and built two boxes for the speakers. Bought a 3way crossover because I had a woofer, midrange, and a tweeter. Wired them up and it sounded great. Sometimes you don't need a calculator to build something, just start building. Tim Allen on the "tool time" show said once, "A good sign of progress is SAWDUST."
adarshnarsaria (author)  framistan4 years ago
just tell me that in the xover high and low frequency i had to enter the range of woofer, mid ranger, or the tweeter