Affiliate Marketing Secrets

Now I do understand a blog niche has to be something that you are passionate about or you will not stay committed into it but another thing is I’m not sure which one to do because they can not be too general of topics either. I have comprised a list and I just wanted some feedback on what would be the best.
• Baseball (MLB updates, playing the game, personal opinions on events)
• Phones/iPods
• Video Games
• Friendships (advice, making new ones, etc.)
• Partying
• Music (dance, reggae, rap)
• Teen’s clothes
• Humour
• Travel
• Hockey
• Past stories
• Inspiration for youths
• Elementary level studies (tutoring)
• Teenagers Lifestyle (a blog for teens)
• Poker
• Family Guy
• The Simpsons
• Big Bang Theory
• Teen life coaching
Alright please give input, thanks.

I just turned 18 at the beginning of this month and this will be my first time ordering my own new cell phone. I have a Droid now but I am getting an early upgrade and will be paying 20$ (I have Verizon) to get a free Blackberry Curve (it was pre-owned. Not refurbished though).
My question is, what does it mean when, on the phone’s page, it says “Phone Requires Data Package”?
It brings me to a page when I click on the link and it says this:
Monthly Data Allowance, Monthly Access Fee, Rate After Allowance
Pay Per Use – $0.00 – $1.99 per 1MB
(Basic Phones Only)
.
75MB3 – $10.00 – $10.00 per 75MB
(Basic Phones Only)
.
2GB2 – $30.00 – $10.00 per 1GB
.
5GB – $50.00 – $10.00 per 1GB
.
10GB – $80.00 – $10.00 per 1GB
.
So if I payed 30$ for 2GB what exactly does that mean? And would it charge me 30$ every month after that or would it charge me only 10$ every month?
Please help me out!
Thankyou to those that answer.