I think im ready to build my first laser!

Ok so I've been doing some research and I just want to clarify some things about building a basic laser. As I understand it, the guts of a laser consists of a diode(obviously), a driver circuit, a module, and a heatsink. Correct?

Alright, now for the most likely dumb questions that I am almost embarrassed to ask.
Does the color of the laser affect how you would have to build it? For example, if you were to build a green laser and a red laser, would there be a difference in how you would build each one or would the process be the same? Would the process also vary when you're dealing with higher level mW?
And i know that a lot of members here house their lasers in a old pen. How would you fit the driver in something that small?

Thanks-Tyler

Yes they are different. Most lasers that people build are red or purple, because those are direct diode lasers. Green, yellow, cyan, etc are all DPSS lasers, which require exact alignment or nothing.

Higher power lasers require better heatsinking but that's about it.

It's all on the driver and the diameter of the laser module/diode

Oh i see. And i heard somewhere that if you have a higher power laser then you have to put more resistors on your driver. Is this true?