Be sure to deduct all of your supplies and mileage you go through to get them.Also deduct your internet since you use it for business to sell stuff and buy materials,and set up a "home office" to deduct a percentage of electricity,phone,etc,Clothes you use to work too
Get Turbo Tax Home Business if you can.It walks you through all of that.It has saved me thousands in taxes over the years because without it Ii would not even know what to deduct.
Also,it is nice to save your reciepts,but not absolutely necessary to have them to deduct things.
Mileage is the most important.Keep track of all of it and if you can set aside one vehicle for all of your "business" stuff,then you can keep track better and deduct tires, oil changes and repairs
Remember that if you don't use your deductions you probably won't make it.It isn't the Government's "right" to take the food out of your mouth,no matter what they try to tell you.