HI, I checked my mom’s belts; they are in good shape and nice and tight; but they squel I think; sometimes; they look dry; Does putting WD-40 a good maintanance step to take. the WD stands for water displacement someone told me; thankyou for your time
No No No wd 40 is slippery. They make a product called belt dressing you can use.
I would make sure the pulleys that the belt runs on are not going bad and dragging
thankyou Hd72; glad I did the double check; I’ll take your advice; have a good new year. 
If the belts are more than 4 years old I would go ahead and replace them. Use a high quality belt like Goodyear Poly-V or Gates. I have a 2000 Blazer that even with a brand new belt (Dayco) is very noisy. The Goodyear Poly-V is the only belt that works on the Blazer.
I’ve used belt dressing in the past, it is a temporary fix and makes a mess of the engine compartment. I prefer just to replace the belt(s) instead.
Ed B.