Yup, good info from Michael...
Rossman, the actual rate you'll be paying depends on your other income level etc. Assuming you had normal taxes withheld from your regular paychecks, you should be pretty much ok there.
Since you haven't payed any taxes on your self employment income, make sure you count on paying regular fed and state income tax, social security and FICA (multiply roughly by two because you have to pay your part and the 'employer' portion), and you'll have to probably pay an underpayment penalty --> The IRS dings you for not paying estimated taxes on that self employement income during the year, unless the amount is small enough.
As for writing off, yes, you can write off most of your business expenses (schedule C), but you have to be VERY specific in what items you are writing off, what percentage of the use of the item is directly business related etc etc. The percentage you can write off as an expense depends on the item and the rate at which you're allowed to amortize it.
Be prepared to document your use of those items (monitors etc) for business use, because it's one of the things the IRS tends to flag for review (having a high percentage of business expenses in relation to business income). In effect, what you're telling the IRS is that you spent more on equipment for the business than what you made during the year........
Of course, without reviewing your entire tax situation, I can't give you more specifics than that
