Was trying to learn myself and thought this might be useful to share.
NIP-01 — Describes the basic protocol flow.
NIP-02 — Defines the contact list and petnames.
NIP-03 — Specifies OpenTimestamps attestations for events.
NIP-04 — Details encrypted direct messages.
NIP-05 — Maps Nostr keys to DNS-based internet identifiers.
NIP-06 — Describes basic key derivation from mnemonic seed phrases.
NIP-07 — Adds window.nostr capability for web browsers.
NIP-08 — Handles mentions (deprecated in favor of NIP-27).
NIP-09 — Specifies event deletion.
NIP-10 — Conventions for clients' use of e and p tags in text events.