[please help make a variable power supply]

Well I could probably live with just varying the voltage so long as I can still get a decent (like 10A) out of it at 12V.  I would be very appreciative if you can explain what I need to and what components I will need.

[please help make a variable power supply]

Yes, I understand that.  But I want to control the voltage and/or current like a benchtop power supply does.  It would even be nice to put an ammeter on it so I can see what's doin'.

[please help make a variable power supply]

Hi folks,
I read through the article below describing how to make a lab power supply from an PC ATX power supply.  The link is here:

http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply

I would like to make this a variable power supply that can generate the full rated amperage.  I will need about 12V and up to 10A on the 12 V setting and up to 25A on the 5V setting.  I am extremely electronically challenged so please be as explicit as possible using laymans terms.  Thanks.