Small Employer Tax Relief Act of 2005 - Amends Internal Revenue Code provisions relating to small business, including to: (1) allow the deduction from self-employment income of self-employed health insurance costs; (2) reduce in 2006 the federal unemployment tax rate; (3) increase permanently the expensing allowance for small business assets; (4) repeal the alternative minimum tax on individuals after 2009; (5) allow certain small business employers a tax credit for the training of highly-skilled employees; (6) make permanent the work opportunity and the welfare-to-work tax credits; (7) increase depreciation and expensing allowances for certain business assets; (8) allow a standard tax deduction for home office expenses; (9) revise certain S corporation requirements; and (10) waive certain tax penalties for noncompliant tax deposits.