At the Brickhouse Inn B&B we recommend that you tour the Battlefield (the National Military Park) with a licensed guide. The guides are licensed by the National Park Service. The standard tour is two hours, for a fee of $55 (for 1-6 people in a vehicle). Typically the guide drives your car, so that you can relax and enjoy the scenery. In our opinion the two-hour tour doesn't do the Battlefield justice, and usually does not include Culp's Hill. A three hour tour is much better - the guide's fee is $82.50.
If you don't want to do the tour with the in-car guide, we recommend that you take a bus tour from the Visitor Center ($30/adult). However, you then have to share the guide with other people, and some time is wasted getting the people on and off the bus at the stops.
A third alternative is the audio tour with a CD. Although the CDs are very good one cannot have any interaction, as one can with a guide. We think the audio tour is best as a 'follow-up' after a tour with a guide.
Something to remember is that guides are very flexible, and will cater for your specific interest, which might be the unit in which your ancestor fought.
For more information contact The Brickhouse Inn, or the National Park Service (www.nps.gov).