Ok guys so today I went out and bought a cigar box in order to build a 6 string blues machine, but I've never built a guitar before, so I have quite a few questions. First off it's 9 inches wide, 12 inches tall, and 5 inches thick, so how am I going to put the neck on? I'm buying a neck off ebay, but seeing the box is 5 inches thick I'm not sure of how to put it on to where the strings will be over the pickups, will I need to put a thick block of wood under the neck and bolt it to the box and to the neck? Also I'm wanting to make it a cut away so I can reach the lower frets, can I just cut off the section that's blocking them from reach? Also if I put an f hole on one side would it make it sound better, or should I just leave the top alone? Thanks guys, sorry for the newbish questions haha Oh and it is made out of pine by the way.
Wow that's a few questions, I'll do my best to help out.

1) The average length from the front of the heel to the back of the bridge is around 290mm (11.4"), so you should JUST have enough room to set a normal Fender neck (assuming a 25.5" scale is what you're going for. It is the worst-case, so most necks should be fine).

2) I would put a length of pine down the length of the box (on the inside), probably the full 5" depth to keep the strength. That way you can route through the top of the box into the pine, and set the neck into that. It'll be much stronger than trying to fix it to the box by itself. Also, use glue to attach the pine, not bolts. It'll keep the wood from reverberating while you play.

3) A cutaway shouldn't matter too much, as long as you cover the new space with something. I would attach a solid block of wood where you want your new cutaway edge to be, then cut it all at once to make sure it takes the same shape.

4) An f-hole will make the guitar moderately louder - if that's what you're after (and most probably would be), then go for it. I don't imagine it would hurt the tone.

Hope this helps, and good luck for the build. Post piccies!
Thanks man, and I just bid on a neck I found on ebay, hopefully I'll win it, and while I'm here do you think you could tell me which 2 humbuckers are best for heavy blues-jazz, like clapton's tone? I love his solo in autumn's leaves, and have you ever loved a woman, I know the tone is mainly from the amp, but are there any pickups that can come close to it? I really appreciate the help dude, thanks (:
Supposedly the Seymour Duncan Antiquity pickups are based on the 50's humbuckers that Clapton used to use, but I really couldn't say for certain. Definitely try them, or at least find some sound clips of them, before you take the plunge - SD are good, but they're not cheap so you wanna take the time to make sure you've got the right ones.
Thanks man, but my dad is wanting me to go cheap first and if it works I can upgrade the pickups, so for now I'm going to throw in 2 ibanez humbuckers out of an af75. I'm really stoked that I'm getting to do a build!