Learning iOS is very progressive thing and you come to learn with the challenges you face. Its best to look in the right place when starting to lean iOS development. Here are the few gems to make you shine as a iOS developer.
cocoawithlove.com – The best iOS Blog by Matt Galaghar which is full of posts with masterpiece code snippets and invaluable advices.
iosdevweekly.com – Its not a blog but have awesome iOS updates every week by Dave Verwer. You can subscribe via email or safari notifications.
mikeash.com/pyblog Mike Ash’s blog. Really good for learning low level stuff.
cimgf.com – Cocoa is my Girlfriend by Marcus Zarra(Core Data Guru) and Matt Long.
nshipster.com – NSHipster is a journal of the overlooked bits in Objective-C and Cocoa. Updated weekly by Mattt Thompson
raywenderlich.com – Ray Wenderlich’s Blog (Really good for beginners). Contains upto date examples.
objc.io – Pretty Awesome upcoming blog by various sources.
cocoacontrols.com – Custom UI Controls blog
petersteinberger.com – Peter Steinberger’s blog
mugunthkumar.com – Mugunth Kumar’s blog
mattgemmell.com – Matt Gemell’s Blog
And lastly there is stackoverflow.com for queries and solutions.