Versailles-tour group or solo?

We took the train, it was so easy. We used the station near the D’orsay museum (we could walk there from our hotel). We purchased the ticket at the station. When you get off, with everyone else, just follow the signs or crowd to the Chateau. It was a nice, short walk. Rick explains it in his book.
We did have a reservation and they stick to it. We arrived at 10:30 for our 12:00 reservation. They have a nice self serve cafe where we sat and had coffee and some pastry waiting for our time slot. Looking at the palace it is to your right hand side.
We used the audio guide which was sufficient for us. A guide might give you more in depth info and of course you can ask questions. Since we used the museum pass there was a seperate fee for the Gardens which you can purchase there. We stayed till about 3:00.

We took the bus one time. It was pretty quick, maybe 30 45 minutes. We got to traverse some nice neighborhoods and got let off in front of the Chateau. It is a 2 minute walk to the bus stop. It is cheaper, 1 ticket for the metro and 1 for the bus. Just another option but fun. Also when you finish at the Chateau you just walk across the street and get on a bus, no walking back to the train station.

How to Get to Versailles from Paris on a Bus. To take a local bus to the Chateau Versailles Rive Gauche station, first take the metro to the Pont de Sèvres station on the western edge of the city. Outside the station, find the bus stop for the southwest-bound #171 bus outside the station, and take the bus to Versailles ...

Finally, there are bikes to rent on the grounds which allows you to see much more. If you take a tour you might miss out on seeing a larger portion of the grounds.