How easy is it to install a car radio?

I have a 94 camaro that has a radio in it someone else installed before me, but it doesn't work. (checked fuses and such)

I found some nice $40 radios at the walmart site, cheap and has everything I need - plug for iphone/ipad.

My question is once I buy it, is everything I need right out the box? How would I go about installing this radio? I've never done this before and pretty low on cash so if I could figure out how to do it myself that would be great.

I could tell you a bunch of stuff, how it can be easy, or super hard.
How you need this, or don;t need that.

Or, take my advice and have a look here, it hands down will tell you everything you need to know, like;

Planning
Video: Find Out What Fits Your Car
What Do You Want to Do?
Outfit My Car

Replace your factory stereo
Video: Car Stereo Installation
Car Stereo Installation Guide

http://www.crutchfield.com/app/promo/diy-car.aspx

Has guides for amps, subs, everything.

I can tell you a few things right off the bat. Cameros no matter what year are typically installers nightmares. If your not savvy working on them you can have a horrible time. Also in car audio you really get what you pay for. Buying a radio that is $40 is going to suck for a few reasons.one the radio is going to come with such a long harness your going ot have trouble fitting it behind the dash.second nearly all cameros are amplified the amp inside that $40 radio will have a 15w per channel RMS which is low.
Now the radio in the car its not the factory chevy radio? Its an aftermarket I assume? Does it work? If there's an aftermarket in there its likely you could match up color for color for the wiring and as long as that radio was wired correctly you may get off lucky. But if its not then that when the horrible part starts.
also the radio will include all parts for the radio not for the car. For instance when doing a Camero for a radio you need a dash kit $20, wiring harness $10-20, antenna adapter $8-15 so the parts are normally more than the cost of the radio. But you may have these parts inside the dash already, If the radio is aftermarket and fits nicely where it is then you likely have a dash kit, if the am/fm radio works then you likely have an antenna adapter. If when you pull the radio out and the wiring doesn't look like a heap of spaghetti then you likely have a harness on it. Personal advice is to save just a little more money and pick up a cheaper radio like say a Kenwood KDC-148 thats just one brand. But go for a renowned brand like Pioneer, Kenwood, Alpine, Sony etc.