Before you just go grabbing Google, think again. Google searching leaves a trail that may let advertisers, the government, and who knows who else know where you have been. You can read about Google and privacy by searching GALILEO. You can also enjoy privacy enhanced Google searching with Startpage.com, Qurobe.it, or Duck Duck Go. You can read more about privacy enhanced searching at The Search Engine and Directory Snapshot.
General Meta Sites cover a wide variety of subjects and are mainly for the general public, though they often contain a lot of both newsworthy and scholarly material. Many have live editors that screen out obvious "clunkers" such as term paper mills and quack physicians selling useless nostrums.
Curlie: Curlie is short for collection of URLs, and uses live editors to add sites to a variety of subject categories. Curlie includes a Kids and Teens category and endless Regional categories to help those planning trips. The Science and Radio listings are also especially helpful. The site is no longer searchable, but the search engine will return eventually.
Dotdash: Dotdash is made of six broad categories: Vacation at TripSavvy, Health at Verywell, Money/Business at The Balance, and Tech/Computers at Lifewire. The site is mainly articles written by Dotdash staff, but they include links, often to primary sources. Dotdash is especially good for consumer, recreational and nonacademic topics.
Google Scholar: Google's search engine for the world of scholarly research. This search engine brings up university departments and government and academic research pages, but it also searches publishers' sites for journals' tables of contents and sometimes even suggests books. Note: the journals seen on Google Scholar are seldom full text due to copyright restrictions.
The Internet Public Library: Once a small, well maintained list of sites and pathfinders (combinations of links with descriptions and references to books and journals), on a variety of academic and academicly related subjects. The pages and links can be a bit old, but the librarian/editors were extremely selective. Alas, the Internet Public Library was last revised in 2012. Please watch for dead links.
Science.gov: A gateway to US Federal Government agencies' funded science and technology web pages and also some nongovernment web sites. The site lists government agency pages and online government publications. There are also featured pages. Needless to say, it is advertising free.