I am a 0L who has never had a job that paid more than 12,000 a year (i.e. still a student). The prospects of making 160,000 are hard to fathom, and I could use some help digesting the numbers.
1) Can someone give me some basic rules to predict after tax income. Paycheckcity is a bit overwhelming but says that NYC 160,000 would leave me with 104,5000 after tax. They break down the 55 some G in taxes as follows:

1a. Is the Federal Withholding constant regardless of where one lives--and what brackets/rates does it use?
1b. Are Social Security and Medicare constant regardless of where one lives--and what brackets/rates does it use?
2) Can someone explain to me how 401K's work. I get that you deduct a certain portion of your income as pre-tax and then can invest that money, and then it is taxed when you withdraw it.
2a. Generally how much can you put into a 401k?
2b. What sort of similar mechanisms exist and how do they differ?
2c. Can you withdraw at anytime (so long as you pay the taxes that year?)
2d. Can you invest the money anyway you see fit? What are the restrictions?
2e. Do most firms offer pensions/what exactly is a pension?
3) How are bonuses taxed (just like normal income?)
4) Is there current data somewhere on the typical lockstep rates/bonuses?
Any help on these questions would be greatly appreciated. I realize these are fairly ignorant questions but Id rather ask then not know!
Thanks