Nomad,
You appear to be in a good spot. I also highly recommend Vanguard. If you read the Wall Street Journal, just about every fund management company has been in serious trouble over something the last 10 years EXCEPT Vanguard. Not sure why, but something there is going on the right way. Almost never a negative story about them.
Anyone's advice to you would be different depending on how old you are? Do you have more than 20 years before retirement? If so, you should be more heavily invested in riskier things (stocks) in your mutual funds. If you don't want to manage that all, then look into the Vanguard funds that change the percentages over time (as someone already mentioned). If you think of yourself as a more hands-on investor, then do it yourself and change things around when the climate calls for it.
You've got $120,000 to work with. Assuming you keep $20,000 in a more liquid account, let's see what $100,000 does over 30 years. At 8% return a year, if you NEVER add to it, that $100,000 in 30 years will be worth $1.08 million. If you kept that $20,000 in a money market account and got just 4.5% from it, in 30 years that would be worth an additional $78,277 for a grand total of $1,158,277, and that's if you never add to either again. Of course if you are older then you won't earn as much before you retire.
If in 30 years you kept that $1,158,277 in a safe investment vehicle that got 5% return each year, you would have $57,913 each year without tapping into the principle. Not bad, but you probably want to invest more along the way so that in 30 years you've got even more. As much as you can as early as you can is the key.