Adding new fields to WP-Posts

Hi I want to add these additional fields to the wp-post table

* photo_url:
* photo_date:
* photo_long_dec:
* photo_lat_dec:
* photo_category:
* photo_filename:
* js_key:
* photo_pre_th_url:
* photo_bot_th_url:
* photo_big_th_url:

but I am new to all this and do not know where to start
thanks
Mike