Hey Matthew,
Here’s a brief and maybe sketchy idea of the whole process. You will need:
(1) Apple Developers license to get an App onto a device and the App Store. ($99./ £61 approximately).
(2) An intel based Mac of some sort, with Unity iPhone or iPhone Pro installed. You’ll also need a device to test on is a very good idea for all sorts of obvious reasons.
(3) You’ll need to download the Apple SDK - including xCode and iOS elements - keep away from version xCode 4.0 and iOS 4.3 for now as it seems something in there gives Unity Apps a problem, they fail Apps review system. Unity and Apple know of the problem. xCode 3.2.5 and iOS and 4.2 are what you should look for for now - are available still if you can locate a link)
(4) When you get your Apple Dev license you get access to iConnect and that’s where a lot of reading will be necessary if you want to make it a painless process, it’s not too hard, it’s just fiddly and somethings can be quite frustrating, so rely on help from the forums.
(5) Once you begin you’ll need a provisioning profile from Apple, you’ll need an Apple ID, and to register any development devices with iConnect website. You’ll also need some certificates which the website will help you download and install into your keychain access.
(6) Make sure all your software is in sync, so whats on your device, itunes, SDK, and xCode all will work together.
(7) Get some graphics and a great idea and make an App in Unity iPhone, test it on your device as you go. The remote sends low quality jpegs to the device as you test it, so you can see how input works (but the visuals are obviously very poor to look at). Once you deploy to the device you’ll see it looks fab.
(8) When you are ready to deploy the finished App, you need a Distribution Profile which you get from iConnect (more reading!). This you install and compile the final version with, which you then check through xCode and zip.
(9) Finally you enter a load of details on iConnect to let the website know what it should expect, what its called, graphics which will be used on the various devices as icons etc. You decide on a price, where it can be sold in the world, what the description is, which places you want it to be i.e. kids, arcade, action, adventure (under games) or whatever.
(10) You download the uploader App and attempt to upload the app.
You’ll be told by the uploader whether the technical requirements have been met, but then Apple will review your App by hand and make a decision as to if it can be published or not. Also somewhere down the line, you may be asked to set up banking details and fill out tax forms, if you are charging for the App.
Hope this helps.