(FORTUNE Small Business) – This year being smart about taxes means focusing on the recent Tax Relief Act. In theory the new law is stuffed with goodies for well-heeled business owners like you. Here are three areas you can't overlook:

ESTATE PLANNING. If you've begun the estate-whittling process, which is essential to minimizing estate taxes, pay attention. The new law will cause the estate tax credit--the amount you can pass to heirs free of tax--to rise from $675,000 this year to $3.5 million in 2009. During the same period, the estate tax rate drops from 55% to 45%. Then, in 2010, a bonanza: no estate tax at all. But the following year, the credit drops back down to $1 million, and the estate tax rate shoots back up to 55%. First you see it. Then you don't.

This lovely illusion of tax repeal means that while you probably won't need to make wholesale changes in your estate plan, reviewing it is mandatory. For example, if you've set up a credit shelter trust and a marital trust to shield heirs from estate taxes, the amount allocated to each trust is governed by a formula. The formula will allocate more of your estate to the credit shelter trust as the estate tax credit rises, and less to the marital trust--unless you change it, explains Walter Van Dorn, an attorney with Kirkpatrick & Lockhart in Boston. Don't ignore new capital-gains-tax rules. A change in how appreciated assets are valued in 2010 could trigger a large capital-gains tax for your heirs.

FINANCIAL PLANNING. Beginning next year, your company can offer a new benefit to employees--financial advice--and pay for it with tax-free dollars. This year start evaluating the services offered by financial planners and third-party vendors such as Financial Engines in Palo Alto, ClearFuture from Morningstar in Chicago, or ProManage in Spokane. Also find out whether your accountant's or attorney's services can be unbundled into separate components, so that next year the advice portion can be charged to your company.

RETIREMENT PLANS. A raft of revisions to employee retirement plans signifies one important change: Both you and your employees will be able to sock away more money over the next six years. First, the limit on what each of you can contribute to a 401(k) scoots up to $15,000 in 2006 from $10,500 today. Individual limits on Simple plans, which are inexpensive retirement plans for companies with fewer than 100 employees, rise to $10,000 from $6,500 now. And workers ages 50 and older can catch up with extra contributions. Second, the percentage of overall contributions from employers and employees is moving next year from 25% of compensation or $35,000, to 100% of compensation or $40,000. Finally, the portion of your salary that can be used for determining contributions and benefits jumps up to $200,000, from $170,000.

Because your job is to max out on all retirement savings, those changes mean you'll require more cash over the coming years. One revision in the law will help. Employers will be able to deduct up to 25% of compensation, rather than 15%, for their contributions to a profit-sharing or stock bonus plan.

These are some of the significant changes to prepare for, but don't ignore the rest of the tax bill. Pay special attention to revisions on educational savings and payment plans, which may affect the way you save or pay for your kids' college and private-school tuition. After all, if you want to mine the middle word from the Tax Relief Act's title, you'll have to do more than collect that rebate check.