Tax write offs how they really work?

Im about to graduate college and start my own buisness I need some help. This is going to be a joint partnership, me and my brother.
I need advice on write offs. We are starting a roofing buisness and I know what items are write offs, however I was always told that the more you buy in practicle terms you save more.
I assumed, now that I think about it very foolishly, that if you owed say 10,000 and bought 5000 in items that qualify that you could save the 5000 and only pay the remainder to the irs. This is way off, correct?
Does it work like if you were to make 55000 and spent 5000 on legitmate items then you only have to pay taxes on a income of 50,000? and then that amount would depend on your tax bracket? I think I got it....
Also how does charity donations work. I mean I dont want to donate just to write it off. I want to actually start my own non profit childhood cancer fund, was wondering how much I could donate to a charity and if thats deducted like the items are.
Txs

In income tax calculation, a write-off is the itemized deduction of an item's value from one's taxable income. Thus if a person has a taxable income of $50,000 per year, a $100 telephone for business use would lower the taxable income to $49,900. If that person is in a 25% tax bracket, the tax due would be lowered from $12,500 to $12,475. Thus the net cost of the telephone is $75 instead of $100.

For most people, the limits on charitable contributions don't apply. Only if you contribute more than 20% of your adjusted gross income to charity is it necessary to be concerned about donation limits. If the contribution is made to a public charity, the deduction is limited to 50% of your contribution base. For example, if you have an adjusted gross income of $100,000, your deduction limit for that year is $50,000.
The phrase "writing off" is sometimes used in a way that suggests the item will be free. The value of the item is only deducted from taxable income, not from the tax itself. The term is also loosely used to refer to an item which is intended for personal use but which will be deducted ("written off") as a business expense. Some individuals attempt to amass large numbers of "write-offs" in order to reach a lower tax bracket and increase the effective size of the deductions.
Charity
The rules on 20% limits and 30% limits are way too complicated to delve into in this space. If you are giving to organizations other than those mentioned above, first consult with your tax adviser to determine whether these other ceilings will apply. If you give an amount in excess of the applicable limitation to charity in one year, the excess is carried over for the next five years.


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Your first description is not correct, your second one, where you say "I think I got it" is correct, except that you also get to take a standard or itemized deduction and an exemption from your net income before calculating your income taxes - the standard deduction is separate from your business expenses.

Expenses that are part of your business are deducted from the business income before your self-employment (social security and medicare) taxes are calculated. The standard deduction and exemption are subtracted after that.

If you're thinking about starting a non-profit foundation, you need to talk to a CPA - it's way too complicated for anyone to guide you through it here.

Don't know where you live but have a awesome tax lady that knows it all. What I do know is you can take a loss for up to so many years and get money back, not pay. Do not consult anyone that tells you to pay 4 times a year into taxes. All gas, mileage, maintenance,equipment, etc. is a right off, including postage, office equipment, office space in your house, phones, lunches, etc. People you employ, 1099 them. You have know clue what is a right off and it can be lots. You can get money back every year if you play it right!!! We all, small business owners need to stick up for ourselves, other wise the government takes it all. They double dip on everything we do for our own business. Please find someone,accountant, that helps you, don't go to anyone like hr block, find a private,reliable,licensed, tax person. So if something would ever come up, they are responsible. Do not do them on your own!!!!

The 2nd write off is right,