https://airbnb.com
I have used Airbnb rentals several times. In Hawaii mostly. All have been good experiences.
When choosing a place, look at total cost. What gets thrown in your face initially, e.g., "$125 per night" can grow rapidly. First, you have the Airbnb "service fee". This might be an additional $75. Then you will find that most places have a "cleaning fee". That varies wildly between places. One place may charge $50 for that, another may charge $200. The Airbnb service charge is a single fixed amount (in my experience) that is a one-time add-on for a rental, no matter how many days you stay there. The cleaning fee is also a one time amount, but I seem to recall seeing this charge sometimes go up for longer stays when compared to shorter stays. I can't say with 100% confidence that I have seen cleaning fees rise with longer stays, but I believe I saw that in some listings. Personally, for everything I have rented, the cleaning fee was a fixed amount no matter how long we stayed. Where you're gonna get hit is on a bunch of one night stays. Those cleaning fees will add up. Stay at one place for a few days and the cleaning fee is spread out over those days and makes the total price more palatable. Also, when you're looking at an area on an online map you will see lots of popups pointing to locations with their price. You might see $125, then $200, then $185, etc. Don't assume the $125 place will be the cheapest. Those cleaning fees really do vary that much. You have to look at each property and examine the details. And DO read all those details before you book.
You pay up front, when you book the rental online. This is easy. If you cancel, you do that online too, and it is just as easy. Note that some places will charge you a cancellation fee or some percentage of the original rental fee even if you cancel immediately after booking. Other places will let you cancel for free for 10 days or two weeks or something. Other places will let you cancel for free right up to 5 or so days before the date the rental starts. The cancellation policy for each property is clearly explained on the webpage where you book. I have had no trouble finding places that let you cancel right up until a few days before scheduled arrival, so I always specifically seek these out as a first choice.
Look for places that are being offered by "Super Hosts". These are people who have rented a lot and have a lot of customers. Read the reviews. Those can tell you a lot about the hosts and the properties. Personally, I have found reviews talking about the hosts to be very accurate. Maybe they all aren't accurate, but for the places I've rented at, they sure seemed to be.
Some places you will be in a house with your host. They are renting out spare bedrooms and such. I haven't gone for the ones where you have just that - a bedroom. I book places where you are in a separate section of the house all to yourself, often times a cottage in the backyard, etc. With a separate entrance different from the main house. Sometimes I've rented the entire house. Some places you may never even see your host. Instructions on how to enter the place (door lock combinations, etc.) are automatically sent to your cellphone a few hours before scheduled arrival. Other places your hosts are very helpful and generous. My favorite place in Hawaii the hosts bring all kinds of food and fruit down to my section of the house. They invite me up to home cooked meals with them. I mentioned that my daughter lives down the street and they threw a dinner party for us and my daughter and her husband. They became great friends with my daughter and do all kinds of stuff together now. Last time I was there they said they were heading to the mainland for a month the following year, and I could come live in their place - the whole place, not just the Airbnb section - if I wanted. I have never had a bad host. Some are just more friendly and outgoing than others. Every place I have rented has been spotlessly clean (but maybe that's because I read all the reviews before booking, and only book the outstanding places).
Other places, it appears that the host bought a condo or property with the specific intent to rent it out on Airbnb. If you faint when you see the prices at a high end Hawaii resort, look for an Airbnb like this. Many of those mega resorts have a separate building on the premises of condos sold to people. You can often find one of these condos for less than half the price of an equivalent hotel room at the resort. And you might find that Airbnb room still available when the resort itself is booked full.
You cannot see the exact address of the place you are booking until after you have booked. They only show you an area that is maybe 2 square blocks. This is good enough to get a very good idea of where you will be. The property listings show general pictures of the place. How many pictures, depends on the specific host/property. Generally I will book, get the actual address, the use Google Maps to find it and look at it from every different angle and street level view. If I don't like it, I cancel the reservation - because I always go with places with generous cancellation policies. I even had one property on our last Hawaii trip that was reserved for the second half of the trip, during week two. We drove by the address during week #1, decided that place was not for us, and canceled (for free). Of course we booked a different place before canceling the first place. I mean, the place was OK looking, but we were into a little more high end on this particular trip. It was not a money-saving trip. You can use Google Maps without an exact address and scroll and zoom to the area and get a general feel for what it's like there, even if you can't figure out which is the exact property. Most properties have a picture of the front of the place on the reservation page and you can use Google's "street view" to drive up and down the streets in the area with your mouse and find the exact place without too much trouble.
If you need to rent a car, the equivalent of Airbnb for houses is "Turo" for cars.
https://turo.com I have used Turo once, on our last Hawaii trip. My experience was fantastic. I will definitely use Turo again. You are renting somebodies personal car, with the Turo company overseeing things, just like Airbnb oversees home rentals. "Somebodies personal car" does not mean their old junker that they drive to work. It appears that many people buy a fleet of new cars for rental on Turo. We have a friend who bought 19 cars specifically to rent them out. I can't imagine how much 19 new cars set them back, but they say they rent like hot cakes and even with the insurance, maintenance and cleaning they have to do (they contract that out), they are making a good profit all around. And for the customers, these Turo rentals are cheaper than Avis/Hertz/etc.