how to file taxes as online contracter so that you can use laptop/computer purchases as write-offs

Assuming you've made above the Federal and State amount for filing a self-employment form (Form C), you would fill out the Form C (self-employment reporting), which asks about expenses related to your business.

You can file as a "sole proprietor" of your business. The form does ask for a simple explanation of the nature of the business.

For an expense as substantial as a computer, you should keep purchase receipts, credit card statements, etc. in case you are asked to include/provide them.

Use a local or online tax preparation service. I think that purchased capital assets with an expected life greater than one year, like a computer, may need to be depreciated over a period time. The IRS has a schedule that lists assets and acceptable write-off periods. Also, you may have to report the percentage of personal vs. business use for all assets and expensed items that obviously can be used for non-business purposes.

Q.

If you file online, like HR-Block, they will walk you right through the steps!