Moving LR3 from PC to LR4 on new laptop?

Hi,

I'm not sure if it's the right place to ask  question about Lightroom, but i'll ask anyway and hope that someone can shed me some light. here is a scenarios :

1. I have LR3 on my PC (folder structure is not neat). I want to move LR3 and digital files (around 400MB) to my new LR4 on the laptop.  Of course i want everything on external drive.  Is it easy to do it? any instruction or workflow sample would be greatly appreciated.

2. Any tips/hints to organize folder in LR?  ( i normally order files by camera type such as 10D, 5DII and actual folders underneath listed by date_place)

3. Do you you both LR4 and Adobe bridge?

Thanks very much.