If you are going to buy an iphone read this before you do. This will help you use your iphone to the fullest.
First of all get GPRS activated on your Sim card. Iphone has a super browser and almost all the things on iphone need GPRS. Like the stock, weather etc. Also try to get the unlimited package because you will be using it a lot.
If you have a computer then try to find a way to sync your contacts etc with outlook. Once you get iphone it will sync all the details available in outlook to your iphone.
Download itunes and put all your music on it and organise it the way you like. Don't for get to put album covers. Since most of the songs from india don't have way to get album covers in itunes you can add them manually. By cliking on each song and selecting get info then just drag the picture you want as your ablum cover into the artwork window and click okay and itunes save that photo as your mp3 files art work or album cover.
If you do this when you browse the mp3 on iphone with coverflow it will look cool.and will be helpful in getting to the song you want quickly.
Also convert all your videos into mp4 format because iphone only plays mp4 format. There are plenty of software that do free video conversion to mp4.
If you get all these things in place you will have an easy transistion to iphone.