Creating gridded photos

Hi,
Apologies if what I am asking is very simple – I’m new to WordPress.
I’m wondering how I would achieved gridded photos – See these url for examples of what I mean
http://www.prolocosantacroce.it/blog/
http://demo.onedesigns.com/pinboard/?page_id=20

Also when looking at the Demo provided on here by designer – how do you make your posts go to into two columns? (i.e morning latte and black nail polish post)

Thanks in advance for any help it is much appreciated
Jill