I have travelled with my dogs for years and always love having a chance to do it. But remember, having the dog along will mean that you will have dog related things to do which may intrude on your vacation time

. It also depends on the vacation. For something like a trip to WDW that involves air travel paired with us being out all day it's a no brainer, my girl gets boarded at the vet.
We recently spent the weekend in Boston, stayed in the financial district near the Harbor & Aquarium. I got up early to walk our girl, nice long walks so that she was tired and emptied

. We would break during the day to come back and walk her again and evenings were more of the same. It was a great trip for all of us...our rottie Bunny had the best time of all

.
Things that I do:
The dog has their own doggie seatbelt & is kept leashed while in the car. I won't take a chance on their making a break for it at a rest stop.
We also bring a travel crate & keep the dog crated when we're not in the room. We decline housekeeping, put the "do not disturb" on the door but it's safer for the dog in the crate. We also bring a kong for crate time...packets of peanut butter make a great treat for Kong stuffins.
We check the room out thoroughly before letting the dog off of the leash in the room...that means under the beds, behind the bureaus, etc with a flashlight. I've found pills that have been left on the floor, things drop and your dog will find them.
Food and water dishes go in the bathroom. Easier to clean up any spills.
Microchip your pet. Just in case they get loose.
I enjoy doing obedience training with my dogs and use trips as training exercises. Sitting in the elevator, heeling while I walk with my bag, etc.
Some Hiltons take pets but by far my favorite pet friendly hotels are the Kimptons. These are gorgeous hotels that are not just pet friendly but pet welcoming. There's a bed and bowls waiting for your dog in your room as well as treats at check in. Kimptons do a nightly complimentary wine and light cocktail hour at each of their locations and I would use that as yet another training exercise. Bunny & I would sit in an out of the way spot and I would keep an cheese stick in my pocket, breaking bits off to reward her for her long down stays. We received SO many compliments on how well behaved she was (if people only knew how NAUGHTY this girl was when we got her as a two year old, un-housebroken rescue) and many people hadn't even realized that there was a dog in the reception room. Plus it's so lovely to have a dog that will sit patiently while you drink you wine in peace

.
Remember, too, that a change in environment and water may result in a change in bathroom habits and...er...consistency. On our first trip Bunny didn't poop for two days

. So be prepared. Also be prepared to stop along the way and keep giving your dog water.
Oh one last thing. No matter how pet friendly the hotel not every guest will be pet friendly as well. Just be aware, keep your dog leashed and everybody should be fine.
And have fun!