Several good points above. I've actually taught a couple of FPU classes, but that doesn't mean I completely buy all of Dave's positions. Still - his advice is rock-solid for 95% of all families, whether it's coming from Dave Ramsey or Anton LeVey.
For one thing - I don't agree on Dave's position about having -a- credit card. I travel on business at least a couple times a month, and on many occasions I've had to buy last-minute airline tickets, pay for extended hotel stays, etc. It's very, very difficult to do this with a debit card. The difference - I sit down and pay my credit card balance EVERY Sunday night - I'm not about to take a chance with a late payment, etc.
Buying individual stocks is not a problem -, but, IMHO you need to be able have six months expenses (NOT the same as income) built up first. Once you have that met, no single stock in your portfolio should exceed more that 10% of your remaining assets above and beyond ownership of your home. In addition to doing your homework, you need to buy/sell with a degree of restraint, and purchase enough of a block in order to keep your commission/transaction fees from eating up all of your gains.
If you're not doing this, you're just playing the Wall Street version of "Rock Band".