Grooming is not a vanity issue- it is a medically necessary requirement for some dogs. It is critical that you understand your dog's needs when it comes to grooming requirements.
All dogs need regular nail trims. The longer you let their nails go, the longer the quicks become. What this means is the sensitive part of the nail continues to extend, limiting how much of the nail you can actually cut off. The overall nail length will remain longer because with long quicks, you can only cut a little bit off each time.
Nails should be done every 2-4 weeks or so for best practice.
You can do them yourself of course, or you can have them done with a groomer or vet. Learning to do them yourself will save a lot of extra effort and money!
If you have a puppy, it pays to start early by touching and holding your dog's feet even if they don't like it (they wont). Praise them when they stop fussing and that's when you can let them go, but not when they are fussing. If you let them go when they are fussing they learn that fighting back and throwing a tantrum gets them what they want- which will decrease your effectiveness as their guide and leader.
Short-haired dogs don't need too much grooming in regard to their fur. They don't typically need baths more than once a month (unless of course they get into something). Bathing too much can strip the fur of its natural, protective oils- so if you need to bathe them more often for other reasons/ preference, don't do it more than every 2 weeks.
Long Haired Dogs
Some dogs have medium or longer fur that will stay a regular length, while some have hair instead of fur that will keep growing and requires regular cutting or it will get out of hand.