There's some good info at
Nolo: Law Books, Legal Forms and Legal Software under "Wills and Estate Planning."
Basically, a trust costs more when you're alive but saves money after you're not. A will is the reverse -- it's relatively inexpensive now, but can be costly later.
Living Trust - advantages:
*Privacy (the terms of it are not publicly available, unlike a will that has been probated)
*Easier and faster to get assets to beneficiaries
*Save on probate costs (no lawyers' fees or court costs)
Living Trust - disadantages:
*You still need to have a will. It's not an either or because you can't take care of everything in the trust
*More expensive to set up than a will, partly because you have to transfer all your assets into the trust
*In some states, if you transfer your primary residence to your trust, you lose your homestead exemption and have to pay more property taxes
*You have to keep it up to date when you acquire more assets. If you forget, those assets will pass according to the terms of your will. If you don't have a will, the state where you live will decide who gets what.
Will only - advantages:
*Less expensive than a trust
*Easier to change as your circumstances change
*Less complicated
Will only - disadvantages:
*Privacy - anyone can view the terms of your will after it's been probated
*Slower and more expensive to get the assets to the beneficiaries
*May be easier for someone to challenge the terms