Arduino Power supply

So I am trying to decide how much power supply is required to power everything and how much is to much

Here is the list of items with what it has in the description

Rotary Sensor 5v
LCD Screen +5v
LED Light 3.3v/5v

I am very new to this so advice would be appreciated

Well, you've said what voltage they run from.
You've not said how much current each one needs. Having links to the parts you want to use will help.

There will never be too much power. The circuit will only draw what it needs, typically limited by the inherent resistance to current flow of the parts used.
What there can be is too high a voltage, which can lead to things like linear regulators overheating as they try to dissipate excess voltage as heat, or transistors and LEDs failing when they try to conduct a higher voltage than they were designed for and leading to too much current flow, overheating, and failure (often immediately).

alright so here are the links

rotary sensor

lcd screen
http://www.seeedstudio.com/depot/grove-serial-lcd-p-773.html?cPath=163_164

led light
http://www.seeedstudio.com/depot/grove-blue-led-5mm-p-1139.html?cPath=156_157

The only info on current consumption was from the encoder at 100mA. I would suggest a supply of 1A just to be safe.

I find it funny that Seeed doesn't mention anything about current consumption.