Smart Guidelines not showing and objects not snapping on to them

Hi Chris

We can see from your screen shot that there are pink link lines visible, which tells us Smart Guides are turned on.  They will need either other layers to relate to, or they can indicate the center of the canvas, and other things that I am not remembering. 

With global Extras enabled (Ctrl H) indivitual features can still be turned off, so check View > Show

Same thing with Snap.  Check View > Snap To to make sure the feature you are using is enabled.

If a feature is greyed out, then that tells you that the document has the Grid (in this case) turned off.

You need the appropriate layer selected for Snap to work.

If I want the guide to snap to the red square, then I must have that layer selected.

If I want to move an existing guide to snap to the red square, then I need to have the Move Tool selected?

Does that help? Give us some more detail if I am not covering your issue.

Good luck.