Change number of posts on main page from 10 to 5

Installation went fine and I’ve been experimenting with the look and feel of the template I’m working with – adding widgets, etc.

The only problem I’m having is trying to change the number of posts that are displayed on the main page from 10 posts to 5 or less.

Right now I’m just experimenting, but eventually plan on using Word Press to implement a blog for the non-profit organization that I do volunteer work for.

I attend their PR meetings and know for a fact that their posts will tend to be lengthy. They may only want to display around 5 on the main page before showing the link below them for viewing older entries.

Just to clarify, I did find where to edit the sidebar for displaying a given number of links – I just can’t find where to edit the amount of posts that are actually shown on the main page.

I’ve looked into editing the design theme, but can’t find this option anywhere. I found a reference to “older entries” for the main page, but nothing that specified 10 per page that I could edit. The theme I’m using is “cognoblue”.

Any help would be appreciated.
Thanks,
jp0586