Generally, anything bought specifically for the business can be deducted including but not limited to: software, business supplies, equipment etc. Last I recall, and this may vary state to state, though you may also be able to qualify for a home-office deductable if you use your home as your workplace. Gas is also generally deductable if you keep a record of your milage.
It is always best to keep a receipt or, if online, the transaction ID. My CPA requests them and makes duplicate copies for obvious reasons

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