Help Please

[(static)]

Hello, I am an art student and have no real experience with electronics.
I am looking to build small 1 LED units (they will be mounted inside semi-opaque cubes)
that will turn on when the cube is in the presence of a magnet.

I have messed with attaching LEDs directly to lithium 3v coin cells before and thought this
project would be similar, so I did some research and learned about reed switches and figured I could
just attach them all together. Here are the components I am looking at:

Reed Switches ->http://www.allspectrum.com/store/product_info.php?products_id=1322&osCsid=71d6a14b3766a502cbc54360ce0165bd

White LEDs (might use other colors)-> http://www.moddersmart.com/en/loose-8mm-led-white.html

3v coin cell -> http://www.electotronics.com/ultralastul2025lithiumbuttoncellwatchcalculator3vbatteryretailpack-dl2025equivalent.aspx

Magnets -> http://www.magnet4sale.com/On-Sale-Neodymium-Magnet-N42-Dia-0.375-X0.25-NdFeB-Rare-Earth-magnet.html

My problem is the specifics of this project. Do I need magnets that strong to work the reed switches, or will cheap ones do? I dont know what switching current, breakdown voltage, etc is and would like to know if these components will work together. Also I would like to know if the setup
(3v coin cell -> reed switch ->  LED) would work with any color LED

[Hero999]

Small lithium batteries don't need a series resistor to power an LED because they already have a high internal resistance which limits the current.

For a circuit that will power white, blue or violet LEDs from a 1.5V cell Google for Joule thief, although you might need to modify it slightly to power it from a 3V battery.

There are other questions you need to ask yourself:

Does it need to be waterproof?

How long do you want the battery to last for?

Do you want the battery to be easily replaceable or is this just a single use item?

[(static)]

Thank you Alex and Hero, I guess I should go into a little more detail about the project.
My ides is that I will be constructing a series of about 15-20 cubes somewhere between 3-4 inches.
The cubes are going to be made out thick, semi-opaque velum/plastic, so the material will still be thin
enough to get through an inkjet printer, but sturdy (I am thinking I will need the less powerful magnets).

As for the inside, I will glue/tape (in no particular order or pattern) either one of the LED units or a magnet to each internal plane of the cubes. In the end I hope to get a set of self-powered cubes that have an unlimited amount of configurations and light patterns depending on how one arranges them.

So to answer your questions:
-On a previous project, I used a red LED taped to a 3v lithium cell as a cordless lighting device, and it worked for
almost a week sitting in the hall at school.
-It does not have to be waterproof
-I really don't need to replace the batteries as long as they last at least a day or two
-I am looking for cheapest price, and small size, (so as little components as necessary)
-And I would like to use at least white/blue/red/green LEDs, do I need different resistors for each? 

[(static)]

Alright... I am trying to find the best place to get the parts as I found out that shipping is outrageous unless I were to get it all at one or two places

A few questions:
-Does the mm size of the LEDs have any effect on brightness?
-Would I be able to use one battery per cube to save money, by running about 3 separate reed switch/led loops to the same battery?
-I am thinking I could use some of the magnetic strips you can get at walmart for the magnets, would that work?

[Hero999]

-Does the mm size of the LEDs have any effect on brightness?

Generally no.

Look at the datasheet and note the luminous intensity figures.

The viewing angle is also important, some LEDs are very bright but have a very narrow beam width and appear unlit unless you're looking directly at them.

-Would I be able to use one battery per cube to save money, by running about 3 separate reed switch/led loops to the same battery?

That depends on how powerful the battery is.

-I am thinking I could use some of the magnetic strips you can get at walmart for the magnets, would that work?

That depends on whether the magets are strong enough to activate the reed switches or hall effect seonsors.