How do I update actual costs (AC or ACWP) in Projectlibre?

Hi, 

I am new to ProjectLibre and i would like to add costs to my Gantt chart. I have seen the $0.00 section but cannt find where to put this in. 

Also does this work on a per hour basis or when you add resources will this also add to the cost of the project?

I hope someone can help, it is a shame there isnt a turorial or something on how to use the software. It looks like good software to have but it is taking me a long time to work out how to do things. 

Thanks

Deasha