Here's things that will be useful:

• A computer. Someone with a laptop might be useful, as there's no guarantee that all the puzzles will be purely online
• A smart phone (capable of reading QR codes or other barcode-y things) might be really useful, although not required
• Paper and pencil, or sometimes, a printer
• Teammates!

Here's links to various online tools and sources:

• Wikipedia's Classical Ciphers page: http://en.wikipedia.org/wiki/Classical_cipher
• Text Manipulation: Reversing
• Text Manipulation: Word unscrambler
• AES: AES Encryption/Descryption
• Braille: Wikipedia has a braille translation chart, as well as general information about the encoding.
• UNICODE: Unicode.org is the official source of all UNICODE encodings
• UNICODE character examinier: Compart.com/en/unicode/combining/230
• Various ciphers: Dcode.fr is a great tool for finding various ciphers.
• Audio Spectrogram Creator: https://convert.ing-now.com/audio-spectrogram-creator/
• General Audio Tool: https://www.audacityteam.org/
• Audio Oscilloscope: https://oscilloscopemusic.com/osci.php
• Online Audio Oscilloscope: https://dood.al/oscilloscope/
• QR code decoder: https://zxing.org/w/decode.jspx
• Card Games: http://www.pagat.com/alpha.html
• Deck of Cards: http://en.wikipedia.org/wiki/Playing_card
• Monopoly Properties: http://en.wikipedia.org/wiki/Monopoly_(game)
• Poker Odds: http://www.cardschat.com/odds-for-dummies.php
• Poker Terminology: http://www.seriouspoker.com/dictionary.html
• Chess Openings: http://www.eudesign.com/chessops/
• Flight Statistics: FlightStats.com
• Broadway: Internet Theatre Database has a wealth of information on Broadway shows, actors, and theatre
• Dictionary/Thesaurus: Dictionary.com is a great resource for word related queries. Visca.com is another resource, which also allows searching by regular expression.
• Everything: Wikipedia contains a wealth of usually-accurate information on almost any subject.
• Fonts: Windows and Mac OS have character maps tools to view fonts.
• Movies: The Internet Movie Database has a wealth of information on TV shows, movies, actors, and production staff.
• Music: All Media Guide has a wealth of information about music artists, albums, and genres.
• Memes: https://knowyourmeme.com/
• TV Tropes: https://tvtropes.org/
• Phone T9 stuff: T9
• Country Info: http://en.wikipedia.org/wiki/Countries_of_the_world
• State Flags: http://www.netstate.com/state_flags.htm
• State Info: http://en.wikipedia.org/wiki/U.S._state
• State Mottos: http://en.wikipedia.org/wiki/List_of_U.S._state_mottos
• Time Zones: http://www.timeanddate.com/worldclock/
• US Census Data: http://www.census.gov/
• US Map: http://www.50states.com/cap.htm
• SEC company tickers: https://www.sec.gov/file/company-tickers (archive copy from Sept 2024)
• World Map: http://www.worldpress.org/map.cfm
• Zip Codes: https://tools.usps.com/zip-code-lookup.htm?citybyzipcode
• Airport Codes: https://www.nationsonline.org/oneworld/IATA_Codes/airport_code_list.htm
• Minecraft Item catelog: https://minecraftitemids.com/
• Music Keyboard: http://www.angelfire.com/tx/myquill/KeyboardLayout.html
• Note Frequencies: http://www.phy.mtu.edu/~suits/notefreqs.html
• VH1: Top 100 Music Videos: http://www.rockonthenet.com/archive/2001/vh1videos.htm
• DVORAK Keyboard Layout: http://www.mwbrooks.com/dvorak/layout.html
• Letter Frequencies: http://www.simonsingh.net/The_Black_Chamber/frequencyanalysis.html
• Phone Keypad: http://www.cs.sunysb.edu/~skiproj/tel2/phone.html
• QWERTY Keyboard Layout: http://en.wikipedia.org/wiki/Keyboard_layout
• Tarot: http://www.learntarot.com/cards.htm
• International Astronomical Union: https://www.iau.org/public/themes/constellations/
• Web/HTML Colors: http://www.w3schools.com/html/html_colors.asp
• Anagrams: Andy's Anagram Solver is a great way to take the word "nagamar" and turn it into "anagram".
• Crossword puzzle clues: OneAcross can take crossword puzzle patterns and/or clues and find the word needed to fill in the puzzle. Crossword Maestro is also a great tool for visualizing crosswords (and Cryptic crosswords).
• Crossword to spreadsheet parser: http://www.npinsker.me/puzzles/crossword/
• Cryptic crosswords: Wikipedia has information and links about these types of puzzles.
• Nonograms: For all you CS gurus, writing code to solve these is always fun. Check out The World of Cryptopics for information on where to get started solving these.
• Bones of the body: http://www.meddean.luc.edu/LUMEN/meded/grossanatomy/learnem/bones/main_bone.htm
• Tower of Babel: https://libraryofbabel.info/
• Periodic Table: http://www.webelements.com/
• When all else fails: Bing, Google