Is it better to start how to code in Objective-C for the desktop before you venture to the iPhone?

For what it's worth, a comment from another newcomer to iPhone development...

My background - I was a C Programmer about 15 years ago and since then I've moved around technologies quite a bit - I'm now an Adobe Flex developer in my day job. By night, however, I'm trying to transform myself into an iPhone developer ;-)

So I bought a book on iPhone SDK development - 'iPhone in Action'. I also bought 'Programming in Objective-C 2.0'. I thought I'd be set with these two but after a couple of days reading and working through exercises it was clear that... I was hopelessly lost!

So I bought another book - this time, 'iPhone SDK Development' from the Pragmatic Bookstore - this is a work in progress book but looked 'right' for me. Turns out this book took me further - it's a great piece of work - however, the early chapters were paced nicely and I was able to follow along and then all of a sudden they began to assume I could recall perfectly the lessons learnt and the procedures followed in earlier chapters and I began yet again to flounder a little - the worst thing I find when trying to learn something from a book is to have to jump around from place to place constantly to make any sense of what I'm meant to be doing.

So (yeah, I know... but bear with me...) I bought ANOTHER book... 'Beginning iPhone Development' from APress. Now THIS book assumes nothing. For a beginner to iPhone development, THIS book hits the target. No jumping around necessary and finally I found I was progressing.

However, what I'm finding is that ALL three books in CONJUNCTION with one another really seem to provide me with a more complete picture - collectively I have a great set of tutorial and reference material. The Objective-C book I've not touched on so much yet but I expect that to be what I need it to be - a reference manual for the language; I'll not need that until I'm much deeper in to the guts. I'm slowly emerging from that horrible "in at the deep end and I can't swim very well" feeling to one where I can at least tread water. Hopefully with a bit more paddling I'll be able to touch the bottom - certainly my confidence is returning ;-)

So anyway, to address the original question - personally if I did this all over again, I don't think I would have gained anything by starting out building for the Mac first and then to the iPhone. I would definitely have lost less hair had I bought the APress book first - that for me was the book that made complete sense of everything for me. I think then the 'iPhone SDK Development' Pragmatic book was the best backup/followup book. This is the path I've suggested to a colleague and I'm confident it's a good one.

Hope this helps!

Jamie.