It is a good idea to have the home inspected. An inspection should determine the condition of the plumbing, heating, cooling and electrical systems. The structure should also be examined to assure it is sound and to determine the condition of the roof, siding, windows and doors. However you should also have a licensed contractor evaluate the property in conjunction with a home inspector to provide the how to and cost knowledge to areas needing attention.
Most buyers prefer to pay for these inspections so that the inspector is working for them, not the seller. You may wish to include in your agreement of sale the right to cancel, if you are not satisfied with the inspection results. In that case, you may want to re-negotiate for a lower sale price or require the seller to make repairs.