Assuming you are a sole proprietor or single member LLC, you will file the Form Schedule C with your 1040. If you look this up, you'll see that their are line items for each expense category (advertising, supplies, travel, wages). You put the year's total on each line. You don't include the backup documents or substantiation with the return. You keep that information for your records in case there is a notice or audit in which the onus will be on you to support the deduction.
Be advised that you have to capitalize startup and organizational costs that are incurred before you start the business, then you can elect to expense up to $5,000 of those costs. Also, you have to report all income, not just when there's "enough" - what does that mean?
