Le headboard DIY + Room inspiration explained

I've taken longer than I hoped to get to this. Good news is I only have one more paper and a week of finals until break! I'm planning posts as of now.
If you didn't see this post about my room, this will be your first meeting with my headboard. Introduce yourself, shake hands. First impressions? If you love the idea, I'll tell you a little bit more to save you some time. (and money)
My room inspiration started from this post at this lady's blog. I saw it a while ago (honestly, months and months ago. and I'm just now doing someting about it. agh procrastination) and fell in love with the colors and the simplicity. So what I took away from this room: the white walls and the pops of color. And then, the sign, of course. You can see  hers is a giant wall sign. When I first saw this, I just wanted to duplicate that exactly. Then I realized it is exactly what I've been looking for for my plain ol' bed.
My Mom and I tackled this project and finished it in a few hours (shopping trip while it dried, I do recommend that) suffering only from excessive paint fumes and paint up our nostrils.

Needed:
- Vinyl Letters (I used 6 in)
- Piece of Plywood
- Tape
- Black spraypaint
- Tape measure

READ THESE questions before you do anything, and then I'll post some pictures below.
Where can I get 6 inch vinyl letters?
Office Max. These can get pricey, and annoying. Packs come with a certain number of letters and they're about $10. If you need four O's like I did, you have to buy two packs, and not use 90% percent of the letters.
I have a bunch left over that I'm selling for 25 cents a piece. If you need vinyl letters (white, 6 inch) for any reason, you can ask me to say you from spending another $10!

How do you get the tape perfectly straight?
We measured 9 inches down the entire height of the board. We marked it every few inches or so, then took a piece of tape and line it up down the entire board.

What don't you just paint it with a paint brush/ other paint?
I made this off of the few comments Amanda made, and she used spray paint. The one thing I really liked about hers was how the light hit the board. Even on the black you can still see the grain of the wood. I'm not sure if it would look the same with other paint. I also was too afraid that would make it more likely for paint to seep through the letters.

How long did you let it dry?
I let it dry for 4-5 hours. We left and went shopping, or I probably would have been picking at it even earlier. (I'm impatient)

Where did you get the Plywood and what size is it?
My Dad picked up the plywood for me from Home Depot, I believe. Plywood comes only in 4x9. I needed mine 5 feet wide for my bed. You can take it to a lumberyard to get it cut! (It looks better when they do it). This is one of the things I was worried about because I still wanted it taking up most of my wall. turns out 4x5 isn't as short as I thought it would be.

How is yours attached?
I attached mine right onto the wall with four screws. I wanted it flush with the wall, so I didn't want it on my bed.

Keep in mind this is extremely customizable. Don't like the wood grain? Paint it a different color. Different font, anything!

Hope this inspired you as much as it did me. If you have questions, ask away.
Happy almost break (for me)