I work for a non-profit which has a very low (almost non-existant) budget.

When I started work, I agreed to use my personal laptop, which I had purchased about 2 years prior, as my work computer because they could not afford to provide the equipment I needed to do my job (marketing, PR, web design, etc.). Besides just the laptop, I also pay for software and upgrades that are used solely for work.

I use my laptop for work 90% of the time and I have a separate home computer for home stuff. It seems like there's tons of info on the web about using a PC for work when your work provides a computer for you, but nothing about using your own PC for work when work doesn't provide a computer and it is required to perform the job.

How can I deduct this from my taxes this year?

If you itemize because you are paying mortgage interest or because you have high state and local income taxes, then you can deduct your expenses associated with the laptop use as an employee business expense.

You will need to fill out Form 2106 and claim the costs under Miscellaneous Deduction on Schedule A.

The laptop deduction by itself is NOT enough to itemize, however.