Well, it sounds like you have $3600 in gross receipts and $460 in expenses for materials, you would report it that way. You should be reporting these expenses on schedule C and paying income tax plus 15% self-employment tax, so its hard to see how you would be due an additional refund instead of owing something like $800 in tax. Maybe you are low (or "low-ish") income, and now qualify for more EIC or the Additional Child Tax Credit. It's hard to know without seeing your return (which I can't and don't want to do).
In general, when you are self-employed you are expected to keep accurate records of your income and expenses for at least 3 years after you file your return. Depending on the kind of work you do, you might have deductible expenses for a home office, for travel, or for supplies and equipment, but it's hard to be specific without knowing more.
