If you're looking to simulate a bunch of 7400 series logic, you might want to download Altera's (now Intel) Quartus II software. It's FPGA / PLD design software. However, they have schematic entry and a 7400 series library that you could use as well as simulation tools. The 7400 series library isnt complete, but it does have a *lot* of those classic components .
If you're planning on making a PCB, this won't help ... But if you want to see how a circuit works (or is supposed to work), you might want to check that out.
The learning curve is a bit steep, but there are tons of tutorials and the like on their website.
I'll let you know if there's something else out there that I'm forgetting . That was the first thing that popped into my mind when I saw this.