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[Reply #15 on:]

Wow thank you for all the help guys!! You all have been so helpful. As a final check, CrossRoads, would the example transistor you linked be fine for what I'm looking for? Is:

http://www.fairchildsemi.com/ds/MT/MTP3055V.pdf

just as good? I can have that transistor here by Friday off eBay which would be great!! If not I'll do some searching on DigiKey for a better one following your specifications.

And last, what resistor should go before the MOSFET? I feel like I ask this question too much but I want to make 100% sure I have everything correct before I begin building my LED strip!!

[Reply #16 on:]

No, that is not a Logic Level MOSFET - all the switching times & currents are rated at 10V.
You want one with ratings at 4.5V.

The gate transistor is determined by the current flow you want out of the arduino.
Gate capacitance looks like a short to ground being charged up initially, or a fully charged cap being discharged.
If we limit the current to 35mA:
So 5V/35mA = 142.8 ohm, so a 150 ohm resistor would allow fast charging while not overstressing the IO pin.

[Reply #17 on:]

Alright, thank you so much CrossRoads and everybody else for your information; it's all been incredibly helpful in my understanding of transistors. Hopefully the MOSFETS get here by the end of the week so I can build my circuits!! Everything works perfectly right now and waiting to get my MOSFETS and everything should be great.

Thanks again everybody!