If you’re new to From the Diary of an App Developer, this is a weekly column where I share my experiences, tips, and overall expertise on application development with you. This is the fifth week, so you aren’t too far behind, but you’ll probably want to start out with the first article.

Your iPhone app is really starting to come together. The design needs a bit of polishing, and, sure, there’s nothing programmed yet, but the hard stuff, the navigation and features, are all over and done with. Nothing else creative, per se, is required any more, just some tedious programming, polishing and of course marketing.

So, without further ado, let’s jump into the programming.

Step One: The SDK

The most important tool you have as a programmer is the SDK (Software Developer’s Kit). It is the tool for iPhone app development. The iPhone SDK is to programming what the utility belt is to Batman. Without the SDK, there would be no iPhone applications. Therefore, learn the SDK. Love the SDK. Become one with the SDK.

This will not come easily, and it isn’t something that can be taught. Although the format and functions of the SDK are fairly straightforward, and, like all Apple-y things, it is rather intuitive and natural to use, it does take some getting used to. Regardless of how many years of previous programming you have under your belt, developing for a multi-touch interface like the iPhone is a completely new experience.

So, now that you know how important the SDK is and how hard it is to master, go and download it now.

Step Two: More on the SDK (It is really important, you know.)

Before we can get to the good stuff (your actual app), you have to master the basics of app development. I know you don’t want to hear this, but it will be at least a month before you’ll have your application’s core features programmed. Programming is a delicate operation, and practice makes perfect.

So, for this week, have the design side of the team focus on polishing up those Photoshop screenshots of your app you made last week, and have your developer get very, very familiar with the iPhone SDK. A good place to start (after downloading it, of course), is the following list of links. Many are tutorials that will lead you through how to make some basic apps. But, I also encourage you to do a lot of exploration and experimentation to learn how the SDK works. Don’t get frustrated or worried; it will be tough at first, but you’ll get the hang of it.

Step Three: Practice with these Links

Your First iPhone Application

Build an RSS Reader

“Hello Universe”

“Hello World”

Interface Builder Tutorial

iPhone Dev Forum

Interface Builder Video

There are tons of other resources online and at the bookstore. A simple Google search can go a long way, but this list of links is a great starting place to get your SDK-kung-fu rocking and rolling.

It may seem like a short lesson this week, but this is the most crucial part of the process for your programming team, and it will all be worth it in the long run. A strong and well-versed programmer will only make the final application that much better. Don’t dwell on what your app isn’t, but think about how far you’ve gone so far. Work hard on revising those screenshots, and focus on your SDK training. Remember the wise words of the philosophical Muppet from Dagobah: “Do or do not…there is no try.” (Or somethig like that.)

Good luck. Next week we’ll get even closer to your final unveiling at the App Store!