Though you may not consider yourself wealthy, this questionnaire will give you a good idea of the possible questions the IRS will ask you upon audit. Read it and plan to have you tax return prepared based on the types of questions you may be asked later on audit. Audits usually do not occur until 2-3 years after the return is actually filed. Remember, when audited if you have written documentation of an item of income or expense, it is probable that the IRS agent will accept that item on your tax return. If you have no written support, it is probable that item will be disallowed.
Do not ever represent yourself on an IRS or State Audit. It is always best to have an independent tax practitioner represent you so you can in most situations avoid talking with the IRS auditor in person and perhaps making statements that will hurt you.