The Nissan Path

I don't use my cruise control much, last time I used it was may be four months ago and it worked.

Today I tried it and both the SET SPEED and CANCEL buttons do not work, furthermore, they used to lit up blue light labels on the dash now nothing will lit up when I pressed any of the buttons.

Any idea where I should start with my diagnosis?

Start with the basics: check your fuses. Also, make sure your brake lights work; if they don't, fix that first. If those are good, then you should get a copy of the Nissan factory service manual for your vehicle. It will give a diagnostic flowchart to be followed for your symptoms. It'll also have a wiring diagram for the system. You'll probably need a test light and multimeter and a basic understanding of electrical troubleshooting to do it.