This is a collection of web links (URLs), which I found useful. As I live in Germany, many of the links of my original version naturally refer to German and Central European resources. This revised and enlarged international version in English dropped a number of specific German items not useful for readers abroad. You find the German version here.

Next to the generally useful www addresses on this page the bulk of the web addresses on my research on the history of computation will be on specific web pages. But this will come later.

internet search   Google Search / Scholar / Books, Bing, webcrawler, DuckDuckGo, Qwant
lexica   Wikipedia: DE / EN, Lueger 1904- / 1926-
dictionaries   Wiktionary, LEO, DWDS, Wörterbuchnetz
translations   DeepL Translator / Write, Google translate, MS Bing translator, Yandex translator

OPACs / Germany   EAH, ThULB, GVK / GVK-Plus / VFL, KVK, DNB, StaBi Berlin PK, Bayerische StaBi, SLUB Dresden, SUB Göttingen, Deutsches Museum, EZB – Elektronische Zeitschriftenbibliothek
OPACs / world wide   ETH-Z / swisscovery, ÖNB, BnF / Gallica, SUDOC, Bodleian SOLO, British Library, Jisc Library Hub Discover, Library of Congress, NYPL Research / General Catalog, href="https://mit.primo.exlibrisgroup.com/ discovery/search?vid=01MIT_INST:MIT&lang=en&mode=advanced" >MIT, Cornell, Stanford, UC Berkeley, Univ of California, National Library of Russia, WorldCat
bibliographic and biographical data bases, search aids, etc.    zbMATH, AMS MathSciNet, MacTutor, zvdd, DBLP, CS bibliographies KA, PubMed, Crossref, ADB/NDB, OGND, VIAF, Archivportal D, Kalliope, GNTUsearch, historicum.net, DBIS
special collections   Internet Archive, bitsavers, Deutsche Digitale Bibliothek, EEBO, ECCO, Cornell historical mathematics monographs, Michigan historical mathematics collection
book trade / antiquarians   eurobuch, ZVAB, abebooks, AddALL used / new, Place des Libraires, Amazon DE / UK / USA

Detailled and comprehensive lists will be compiled for another web site on the history of computing. This is a long term project with slow progress; so I share here only a few special web adresses, which I use in my research next to those listed above.
slide rules   Oughtred Society, RST, NL KRING, UKSRC, ARC, ISRM, Rod Lovett's pages, McCoy K&E pages, Rechnerlexikon, groups.io [sliderule] / [drawing instruments]
patents   DPMA mit DEPATISnet und DPMAregister, EPO – European Patent Office (Suche), WIPO Patentscope

TV   BBC, ARD Tagesschau, ZDF heute, CNN      [programmes (DE): ARD, ZDF]
radio   BBC world service / programmes, Deutschlandfunk
newspapers   FAZ, Süddeutsche, Handelsblatt, NZZ, NRC, The Guardian, New York Times, Washington Post, Wall Street Journal, Le Monde, Le Figaro, Jerusalem Post
German weekly journals   Der Spiegel, ZEIT, Wirtschaftswoche
other sources   Heise Ticker, Wired, slashdot

time   PTB clock, NIST, World Clock, time zone map, TimeAndDate with sunrise/sunset
postal services & tracking services   postcodes Germany / worldwide, 17track, DHL
weather   DWD, Wetterkontor, US National Weather Service, UK Met Office, UK WeatherOnline
travel by car   route planner Michelin and ADAC   and by train   DB Reiseplaner
maps   Google maps, Bing maps, OpenStreetMap

TeX / LaTeX   CTAN search / packages, Comprehensive LaTeX Symbol List, TeX/LaTeX Stackexchange
PC keyboards / typing foreign language texts    (currently just for Germany)   survey on Wikipedia, typing Russian, typing French

and we will certainly have more on that in the future ...