I've been playing through Civilization V this evening #CivV and I think I've found a bit of a hack that's putting me miles ahead of my rivals.
Early in the game, select the current research icon and it opens up the research tree. Now, tell the game to research the highest level tech (I can't remember what it's called, advanced warfare or something).
The game will now automatically schedule the research to get you there in the quickest time.
For reference, I've got to about the mid 1800s, I've just entered the atomic age, and have then moved onto researching a thing called a "compass". 😊