Deadlifts - These are actually looking good, but apart from the first and last rep, the bar was too far away from you at the start of the rep. When you're getting the bar back on the floor, you're bending at the knees first, which isn't allowing the bar to go down in a straight line. You're having to go round your knees, and because you're not resetting the bar, it's ending out a couple inches in front of you when you start the next rep (you can see it clearly from where it's sitting on the plate). Break at the hips first, and when you pass your knees you can bend them (keeping a tight, straight back the whole time of course). Look at your first and last rep on the way up, almost a perfect vertical bar path. You want this every rep, whether the way up or the way down. Don't be scared to completely reset to get into position until you get this. It's better you get good 5 reps.
Overhead press - When you're racking/unracking the bar you don't want it floating about in front of your chest. When it's on the rack, get your grip (tight) and push your elbows forward and it should sit tight against either your shoulders or upper chest depending on flexbility, it shouldn't leave here till you start the rep (and when you're done it shouldn't leave your shoulders until you get it on the rack). The idea is so that if you look from the side your forearms are vertical (would be good to get a vid from the side too). Also, at the end of every rep, you need to shrug up
http://www.youtube.com/watch?v=GJFjYyA40ss (2:20, also the rest of this video is good for getting into position).
Squats - Looking quite good for starting off, though I'm pretty sure you're doing a high bar squat instead of a low bar squat (I done this, and didn't notice for at least 6 months or something lol. so you're better getting a 2nd opinion from someone on here haha). From the front view right before you lifted the bar off the rack you slid your right hand out making the bar unbalanced, it looked like it was starting to cause you problems on the last couple of reps. This will be a BIG PROBLEM with more weight, so sort it out early. I noticed you pull your knees back at the start of each rep but I don't really know if that'll lead to anything bad, just pointing it out. Also it looks like your back bends a bit at the bottom, but this will prob change a bit when you change bar position.
http://images3.wikia.nocookie.net/startingstrength/images/8/8b/Squat_Bar_Placement.jpgFrom the side view when you're at the bottom you get a good view, looks like the bar's on your traps instead of further down. It'll feel kinda weird when you try a low bar position to start with but you'll get used to it.
Btw, don't be discouraged by all this, you're doing really good for someone just learning the lifts. I was making these mistakes for a long long time, because I wasn't taking videos or getting people to help me, they went on for a while. (and my technique's still far from perfect, still got a lot to learn, bad habits and flaws).
Keep up the hard work!