Total Newbie...Lil Help please

I'm totally new to the psp homebrew scene. I just purchased a psp phat from a friend, and I have looked at the links here and other places, but it's a bit confusing and bit overwhelming for a me since i'm new to the psp side of things. I guess basically what i want to do is load a custom firmware. I guess the best is the dark alex one. Basically I want my psp at it's best and full potential. From my readings on the web these are the steps that i think i need to do. I just need clarification.

1.. Need to downgrade system software to 1.5. Mine is at 2.82.

2. A Pandora's Battery?

3. I guess if i did everything right at this point. Load custom firmware, right?

4. What do i do if i brick my system?

5. Whats a magic memory stick and what does that do?

If there are any links that will help me, please post them. I'm just trying to get all the info i can. Thanks. Please excuse my newbie-ness

pandora's battery puts your PSP into "service mode"
a magic memory stick is a memory stick with files that can be read by said service mode
these 2 things together can do 2 wonderful things

1. they can downgrade your PSP from any official firmware to 1.50 or w/e firmware happens to be magically put on the magic memory stick

and

2. they can UNBRICK your PSP if you happen to brick it

Ah, ok, thanks... I like i said i found a few links, so i guess it's time to start messing with it...