How to add a comment on column and table

I would like to have a comment for each column, I know this is possible in oracle we can have comment for each column.

can I have the same in SQL Server, can you provide me a simple example.

I created a table as in attached screen, and tried using the extended properties, to do this. however I've few questions

1. How can I retrieve this info using query  

2. here in point 4 of attached image I see Name and Value, do I have to give name and value for each column

3. Do I have to rt click each column and go and update this info their, I have a table with 100+ column :(

Thanks!

Neil