Just finished installing the heads on my rebuild project and I thought I would reflect on my experience, overall it went smoothly but there are a few things worth thinking about.
1) My gaskets were not marked "TOP" and I was initially confused as to what side was the top and bottom. I did some research and the side with the sealant goes up, so there's that if you are wondering the same thing.
2) My engine is on a (cheap) stand without locking casters. Even if it did have locking casters I would imagine it would still slide when you torque down the bolts so i wedged mine up against the side of my garage to brace it.
3) I used this project as an excuse to buy a semi fancy electronic torque wrench with an angle sensor in it in anticipation for the head bolt install. This worked really well for the con rod bolts and the first 90 degrees of the head bolts, but the second 90 degree turn exceeded the torque capacity (100 ft-lbs) of the tool so I had to figure out how to make sure I was getting a 90 degree turn.
4) I ended up putting my socket on a long breaker bar and putting the socket on the head bolt, after which I marked it with a dry erase marker at the 9 o'clock position, so when my turn was complete it was at the 12 o'clock position. At which point I could just wipe the mark off and repeat with the next bolt. I also used the marker to number each bolt so I wouldn't screw up the order in which I had to do it.

It was quite the workout for someone like me who isn't particularly strong but so satisfying to see it come together!

 

I’ve wondered how you would ever torque head bolts if the engine wasn’t mounted solidly to the vehicle. I also marked my head bolts (but used a permanent marker). I was very glad I did as my wrench slipped off twice during the torquing sequence.

 

Oh man, the thought of my wrench slipping off didn't even occur to me, glad that didn't happen or I would have to guess/estimate how far the bolt had turned because only my socket was marked.

 

I always paint a stripe with a paint pen on the bolt head. Also mark the socket every 90 degrees. It is far better to sneak up on the torque than overdo it.