Terms commonly used in tax practice

I am looking for an explanation or definition and maybe a couple examples of: Income from an "Active Business" Income from a "Specified Investment Business" Income from a "Personal Services Business" I am having a hard time understanding what the differences are between the three.

Alternative Minimum Tax

Sharon, a single taxpayer, has taxable income of $100,000, a regular tax liability of $26,560, a positive AMT adjustment due to limitations on itemized deductions of $20,000, and tax preferences of $25,000 in 2006. What is Sharon’s AMT for 2006? Can you please show me step by step how this is calculated?

Tax Law Case

Case: Gregory v. helvering, 293 US 465 (1935). If you can't open the case you can find at at findlaw.com

Don't let the tax tail wag the dog

The four "maxims" of tax planning are relatively straightforward, and don't need rehashing here. The text also mentions considering "nontax" factors, which is often times a very important and very overlooked aspect of the decision making process. There is a saying common among CPAs that goes "don't let the tax tail wag the dog..." What does that mean?

Advanced Business Taxation

Relate IRC Sec. 351 to the substance over form doctrine. What purpose does the control requirement of IRC Sec. 351 serve?