Short version of the question- what skills do I need to be a hacker?
The required skills are many and varied depending on what you want to do.
Broadly speaking I am going to say they fall into 3 categories
1) Electronics
2) Programming
3) More traditional engineering (mechanical, materials and the like) or science (chemistry, biology and if it did not already fall under engineering then physics).
None is any more important than any other and there are countless subdivisions (electronics falls into digital and analogue as the big two and they divide again, programming runs from electronics right to really high level stuff like HTML and additionally the interplay between these levels is becoming more and more important, 3) I already mentioned a few divisions of) and ways to blur the lines (pharmacology- mixture of chemistry and biology for one) and most hackers will have a grounding in all three and maybe a bit of specialisation depending on what they really want to play with (or not- some of the most interesting things come from people skilled in other areas, for example
http://ds9a.nl/amazing-dna/ and probably the most famous example of all is
http://www.youtube.com/watch?v=pQItB5uoiHI ). For your examples
Light show- depends what you want to do. Simple lights that appear are very easy to add- you simply have to have a way for the light to escape and a way to power the light (LEDs take little power, run at the sort of voltages and allowable currents inside the safety limits of most devices or can be made to run at the sort of voltages and currents easily sourced in most devices)/
Blinking lights can be done, fancy patterns can take more effort (or not if the hardware itself provides a method- see pulse width modulation) as you might need extra circuitry.
Speakers- same idea as lights really except most speaker mods are towards adding better speakers, fixing them or lowering power requirements. You find the speaker access points and either tap the output to run through an amp in the case of upping volume (audio engineering is a field in and of itself) or if it has an amp onboard maybe bypassing that.
Cameras- this one is more tricky. On the one hand you might have a device that already allows a camera and you just need to find a way to attach and maybe power it from the device and hide the wires.
On the other hand it could take something like
http://ladyada.net/learn/diykinect/ and hacking right down into the heart of the device.
"if there is a good place to start....where is it"..... "Of course I can take a part a lot of things"
You just answered your own question. Figure out how to put things back together and you are away. You will start seeing patterns in how things are made and put together (also how shockingly cheap manufacturers of stuff are)
There are other things
http://gbatemp.net/t105493-how-do-people-k...t&p=1406730
http://gbatemp.net/t204149-psp-hacking?st=...p;#entry2541305
http://gbatemp.net/index.php?showtopic=271...t=0&start=0
I suppose all I will say is do not always look to traditional education and means. Not to say it can not be done or is even all that ineffective if you play the system but there are serious shortcomings in it and you can save yourself a fortune in education bills.
http://www.ted.com/talks/lang/eng/temple_g...s_of_minds.html ,
http://blog.ted.com/2010/05/13/math_class_need/ and
http://www.youtube.com/watch?v=zDZFcDGpL4U being three jumping off points for such a view.
Failing that
http://www.youtube.com/watch?v=ymsHLkB8u3s illustrates it quite well too.
