First off I would like to know how many LEDs I can power with one 220 Ohm Resister, do they need a resistor for each one, or can I get a bunch off one resistor? Or can I do something like I wanna power 2 LEDs, I put in a 110 Resistor?
Use the flowing formula to calculate the resistor value.
[latex]R = \frac{Vin- Vf}{If}[/latex]
Vf is the forward voltage, If is the current and Vin is the supply voltage.
Suppose you have a 9V battery, a green LED with a forward voltage of 2.2V and you need a forward current of 10mA.
[latex]R = \frac{9-2.2}{0.01} = 680[/latex]
And how do I go about making these LEDs(9v) be able to plug into the wall? I guessing I need to add some parts to lower the voltage from a normal house plug?
Use a mains adaptor (Wall wart) to convert the mains voltage to a safe DC voltage such as 12V.
Beware that unregulated mains adaptors give higher voltages at lower currents so expect >20V from an unregulated 12V adaptor at light loads and take it into account when calculating the resistor value. Your best bet is to measure the voltage with a multimeter.
Say I setup 10 LEDs, I want to make them have a dimmer, so I get a Potentiometer correct? Do I put at the where the positive comes in before any resistors or LEDs.
It doesn't matter whether the potentiometer comes before or after the LEDs. Look up Ohm's law, the current in all parts of a series circuit is equal.
Using a potentiometer isn't the best way of controlling the brightness a variable constant current source of PWM is better.
Edit: Another question, say I put 50+ of these LEDs together, will they need bigger wiring because I am drawing more power? What about heat, do I need a heat sink?
That depends on the current, if each LED is only 10mA then it's only 500mA so the wire can be thin, if each is 300mA then the total current will be 15A so the cable needs to be thicker.
Edit: One other question, I came across these LEDs at the electronics store call Ultra Red Blue ect. If I put a 'Ultra' Red and 'Ultra' Blue LED next to each other does this give me UV rays? Or does the 'Ultra' mean something different in this case?
No, it just gives you magenta or purple light (depending on the mix).
Look up the electromagnetic spectrum and you'll find that UV is radiation with a wavelength shorter than about 400nm. The red LEDs emit radiation of about 660nm and the blue emit radiation of about 450nm.
Ultra is just a marketing term and means nothing.
You can buy UV LEDs but they cost more than normal LEDs.