A. Retirement accounts such as 401K and IRAs can't be owned by a trust, but the trust can be the beneficiary of those accounts.
Before you decide what to fund a trust, you need to understand the two advantages of funding a trust with certain assets:
1) When you become incapacitated and need someone to step in and handle your estate, it can be seamless with a trust.
2) When you die, a trust will make life much easier for your beneficiaries (if you only have a will, your estate will first have to go through the probate court process, there is no probate with a revocable living trust).
With the above benefits in mind, you can consider putting everything into your revocable living trust, such as your house, your savings, CD, etc. so if anything happens to you, your children can get the money from the revocable living trust easily.