One nice side benefit of starting your own web business is the home office deductions you can get. Now, you shouldn't start an Internet business just to get the deductions, but if you are going to start an Internet business (and you should at least try) anyway, the home office deductions certainly are nice.
If you set up a home office (dedicated just to being an office) you can deduct that on your taxes in proportion to your house payment. So, if you have 1,000 square foot house and a 100 square foot office, you can deduct 10% of your mortgage payment.
You can also deduct portions of your Internet access fees, gas heating bills, electricity, water, phone, and even your cleaning service if you have one. These things can all be deducted in proportion to how much you use them. So, like for the example above, you could deduct 10% of your gas heating, electricity, and cleaning service bill since (as the theory goes) about 10% of those things go towards your office.
Calculating your deductions for phone and Internet access are a little different. If your DSL bill is $50 a month and your online 1 hour a day for personal reasons and 2 hours a day for your business, you can deduct 2/3 of your DSL bill.
We're not tax experts or anything, so be sure to consult your tax preparer/adviser on all these things. But it's most likely the case that for sitting down for 10 minutes and figuring these out, you'll be able to deduct a nice chunk off of our taxes thanks to your new eBusiness.