What receipts do I need to keep if filing taxes as self-employed?

I have been working for my boss since the beginning of Jan 2009 to present. He is not taking out taxes out of my checks. I get a regular check from him every 2 weeks. I am working from home in another state. He is located in FL.
I work M-F from 8am-4pm full-time.
Since no taxes are being taken out, if I am going to need to file taxes as "self-employed", what receipts do I need to keep?
Also, should I go back to H&R Block or should I get an Accountant to help me?

Oh, right, you work MF, 8-4, full time just for him. You are NOT self-employed.

If you want to fight this, file a form ss-8 with the irs and if approved filed a 1040 with a form 8919. You still pay your taxes and your half of the SE tax. Any expenses go on schedule A, where you probably can't deduct anything.

If you don't fight him and let him get away with this, you file a 1040 with a schedule C, schedule SE and pay all of the taxes, including his 7.65%.

As far as receipts go, you won't have much. Long distance phone bills, but not the phone itself. If you are on an unlimited plan, nothing.

Since this is the first time you have filed that way, get an accountant. The accountant's fee is a tax deduction.
Keep receipts for everything doing with your work. This includes phone, internet, medical, gas, car maintenance etc. You can go to the IRS website and download a pdf called taxes for small business, it has a list of all the deductions.
An accountant will be up to date on all of them as it changes often.

He is going to have to provide you with a 1099 on the money he has paid you. That goes to the government. You will need receipts for your health insurance which is deductible, receipts for your computer, telephone, internet access, office expenses. Do you use your car as part of your work? Mileage log. Might also be able to deduct for office space in your home. Do you have a SEP IRA account? You can protect a considerable bit of your earnings if you do. Not to late to set one up.

An accountant might well be worth your money since you do not know a great deal about the ramifications of self employment and how to minimize your taxes.