Is the 720 Windows Phone 8? If so, a few tips:
SMS-if you didn't turn iMessage off, you won't get texts from iPhones. Otherwise you'll get a notification across the top of the screen and see an unread texts count in the text messages live tile (looks like a text bubble). If you want to make sure you're getting texts, pop the SIM back in your iPhone, turn off iMessages, turn off iMessages on all your various iOS devices, then put the SIM back in the Nokia, reboot it, and that should bring texts to your Lumia. There's a more nuclear option of deleting your iPhone from the profile settings on Apple's support site, but that's only useful if you plan on totally leaving your iPhone. I switched from a 4S to a 928 and had to go through that, but once it's all set you can turn iMessage back on your iPad or any other device. It's just a pain to decouple your cell number from Apple's iMessage service, and if you're not thorough your texts end up in limbo. Outgoing work, incoming disappear.
In settings there is something called Data Sense-that will help you gauge what apps are slurping data and how much. You can also set your data cap and have the phone alert you/shut down all automatic data consumption once you get close to your limit.
Microsoft has a great site,
Windowsphone.com, that has tips, how-tos, and a full app catalog. You can also remotely install apps from the site and send them to your phone (just like the Google Play store).
Wpcentral.com is also quite active, and the community there has some great tips.
Good luck! I am enjoying Windows Phone so far. It has the fluidity and speed of iOS, but the customization options of Android...it's fun to try something different.
