Only complaint I have, I really wish most of these telescopes were open to the public. I have never had the opportunity to look through anything bigger than a backyard telescope and it would be amazing to be able to see what a thirty meter telescope can do.
You don't really "look through" them so much as reserve time and then sit in a control room in Waimea, or more likely your home institution anywhere in the world, and wait for digital data. Some stuff is done with a realtime observer making decisions (based on the digital data), but a lot of it's automated and planned on schedules that optimize the amount of observing vs. the amount of repointing and other overhead. There's various ways to get access, but mostly they require being part of a research institution and proposing for time. The various institutions involved in building them get observing time in return, and then some amount is probably also available through gov't grants to "buy" time. A nice thing about ground based telescopes over space based is the amount of effective observing time relative to things like calibration and maintenance, so they're effectively accessible to more people. The number of people on the summit is getting to be fairly small and tending toward the people who are doing construction, maintenance, installation, or any kind of hand-on instrument calibration or adjustment, but observing is moving to be more and more remote, which also makes it more accessible to more people.