Taking payment online - good info?

I'm looking for quality articles or comparisons between different vendors and approaches to taking payment online. For instance....

What approach to take to processing payments for your website, blog, or online business?
1. When should you set up yourself with your own merchant account?
2. When should you just use Paypal?
3. When you should piggyback on your hosting companies credit card relationships?


If you set up yourself with your merchant account:
1. How do you pick a vendor?
2. Should you do batch processing or not?
3. Where is the best listing of available merchant account vendors and credit card vendors?