So I found some code (a PHP class) that almost does what I want it to do. At the top is a phpdoc block with info about the original author and the license being New BSD License.
I want to respect the original author, so what can/should I do if I want to change some of the original code?
Sorry if this is a stupid question.
If you make substantial modifications to the code, its probably a good idea to add your copyright under the original author's.
Something like this should suffice (even if you put it just under the original license):
/*
* Copyright (C) 2009 (your name here)
*
* - Extended foo for bar
* - Optimized foobar()
* - Added handler raboof for reversing multibyte strings
* - Program is now sentient, keep away from children
*/
Keep in mind that the 3 clause BSD is one of the most permissive licenses used today. It also happens to be my license of choice for most things that I release to the public. Most people who release code using it are pretty laid back.
Don't be too paranoid, just show a good faith attempt to detail how your version is different from the original, just so its not confused by someone as being the original.
As others have said, the BSD license is very permissive. My understanding is you can basically do anything with the code so long as you don't claim you're the original author.