guides in blender?

Is there a way to add guides in blender (like in gimp)? I need to measure the length of objects and align them according to another object, how can I do this? Thank you!

Have you tried enabling ‘numerics’ in the Mesh display?
You could snap a lines vertex to one object then snap the other vertex to the other object
to measure distance. Put them on another layer for when you want to hide them.