i need some help with tire sizes and such

i appoligize if this has been asked before but, i cant stand the search function, it never works right for me. can some one help me out, i am tring to plan out the details for a hot rod first gen blazer.

1. what is the difference between tub and minitub?

2.what do the #s in rim sizes mean? example: 15x8. i know the 15 means 15 " rims, but what is the 8? the tire width?

3. can someone explain the #s tire sizes come in.
example: 255 65 15(this is just a random #) i know again that 15 means 15 inch rim, but what do the rest mean?

4. what are the most popular sizes for street/strip applications?

5. how does backspacing work?

thanks guys

Well for starters, a minitub is just a small tub, so you can fit as much tire in there...

This a Porsche site, but this guy explains it all pretty well.

http://members.rennlist.org/951_racerx/WheelsFAQ-measurements.html

255/50/16... 255 is width in mm, 25.4mm to an inch, so thats a 10 inch wide tire. 50 is the ratio of the sidewall to the width of the tire, also known as the profile. This particular tire has an aspect ratio of 50%, meaning the sidewall is half as tall as the tire wide, 10" tire, 5" sidewall. 16 means it's a tire made for 16" wheels.

15x8 means 15" tall, 8" wide.