Please don't get confused about trusts in this thread, if the deceased had a trust in his or her name the ESTATE is the beneficiary of the trust, not you. If there is anything more complicated involved, the executor will be able to tell you.
The inheritence is not income, so you will not be taxed on it. Once it becomes yours and it begins to generate income (assuming you don't spend it all at once immediately!) you are taxed exactly as you are on any other asset.
You are not likely to have a choice about whether or not to take the inheritence as a lump sum or in pieces. It may depend on the timing of disposal of assets (like a house, boat, whatever) and how obstructive whatever institution(s) are that currently hold financial assets (funds, stocks, cash) in releasing the assets out of the estate account. Plus, even after everything is clear the executor is normally instructed to hold back a small portion of the estate until the next tax year. That's just in case straggler bills or whatever need to be paid out of the estate funds.
You should have a chat with the executor who will be able to explain how and when the assets are likely to be distributed.