Some things that I'm about to ask might sound stupid but keep in mind that I'm 17 and have never made anything with wires and resistors or anything like that so I might need some help. Also my dad has been a certified electrician longer than I've been born so he can hopefully help me out.
So I decided to make a tap tempo because I thought it would be a fun easy project to do. I'm also addin a 3mm LED for looks,which will be powered by a 9V adapter. Materials list:

Die Cast Aluminum Enclosure 3.64 in x 1.52 in x 1.06 in
Soft Touch SPST Momentary switch - stomp type
1/4" female jack (input jack)
Purple 3mm LED (forward voltage: 3.2-3.8V. Forward current: 20mA)
300 OHM 1/4watt 5% carbon film resistor
2.1mm DC barrel jack (for pluging in 9V adapter)
24 AWG copper wire - un-insulated

From my knowledge, I just need to connect the input jack to the momentary switch with the copper wire. But which pins do I connect? And I don't need to ad a 3DPT thing or anything like that right?
And the LED. Can I attach it directly to the 2.1mm barrel jack? And which end of the resistor do I connect to the LED.
Please and thanks!
Get the schematic you're working from, and have your dad show you how to read it. If you're using this as a learning project you should learn from it! I think you'll see why I'm not answering this particular question once you get the schematic and switch in your hands.

What are you doing with the LED? If you want it to turn on and off as you tap you're going to need a different switch (and then of course the LED will do nothing but remain on/off once you stop tapping; this might be distracting). If you just want the LED to light up the pedal (i.e., on all the time) you can just wire it up to the power supply. If you want the LED to pulse with your tempo that's not going to happen with this type of build.

Resistors are not directional, so it does not matter which end you connect to the LED. If you meant to ask what leg of the LED the resistor should be connected to, that's also not important. LEDs themselves are directional, so you need to be careful in how you wire them. The cathode usually has a shorter leg, and a flat side to the housing, so that needs to be the leg that goes to ground, and the anode goes to the positive terminal.

Also, just checking: what are you using this tap tempo with? This build will only work as an external tap switch for a unit that already has a tap tempo input.
this parts list is not enough to built a tap tempo. the easiest way I can think of to make a tap tempo is with an arduino, which should be fun and quite easy for a new builder. and the arduino can be used for something else easily for other fun projects if you change your mind about the tempo. I also dont know why youd want an input jack on a pedal that would just blink an LED.

as for the questions, a resistor can be soldered on either end, they are bipolar if you can call them that. you can solder an LED directly to a 9v jack, but I dont know why youd do this.

for the arduino suggestion, its quite easy. arduino has a library of programs already made with instructions, tutorials and suggestions to make your own program. a program to make a simple tap tempo is most likely already included in the arduino software library. and it would probably just need some tweeking to the program. the arduino language itself is very easy to learn and have very useful tutorials on youtube.

for any diy project, I strongly recommend against using uninsulated wire. I fully recommend trying arduino projects out. they are addicting as all hell.
Marty Friedman is GOD!

curently in a SEX MACHINEGUNS and X JAPAN phase AND Galneryus AND Anthem phase

damn J-Metal, why you so awesome

My Gear:

Schecter Hellraiser V-1 fr
Ibanez RG321mh
Fender GDC-200sce
Peavey Vypyr 30 w/ sanpera 1
Thanks Roc8995 and Bustapr.
I'm just having an Led that stays on the whole time when I connect my daisy chanting it. I wasn't going to make it blink or anything. And it's just cuz purple LEDs are cool and it's just for looks.
I'm using a Boss DD-7 - the switch is a NC since that's what boss is compatible with.

@bustapr the input is to connect the tap tempo to tap "tempo/exp" input on the DD-7

I think I saw the arduino project thing when I was on RadioShack.com. I'll have to go back and look at it.

I've seen people make these pedals by drilling two wholes into an alto ides tin and wire the switch and input together but that seemed a little to ghetto for me.
Thanks for the feedback!
Just an update. I looked at the Arduion kits and that doesn't look like anything I would need for the pedal. I'm only making an external tap. From what I've seen, I would use that in a pedal if I was adding an effect to my signa, or wanted my led to flash but hats not what I'm goin for. If I can make an external tap tempo without one I would like to.
oooooooooooh, didnt know it was for Boss pedal. I thought you were working on a sort of metronome...

forget about the arduino thing xD
Marty Friedman is GOD!

curently in a SEX MACHINEGUNS and X JAPAN phase AND Galneryus AND Anthem phase

damn J-Metal, why you so awesome

My Gear:

Schecter Hellraiser V-1 fr
Ibanez RG321mh
Fender GDC-200sce
Peavey Vypyr 30 w/ sanpera 1
Oh ok. I looked that up and got confused. But I've seen pics where there just connect the switch to the output and it worked.