Chemistry LibreTexts - Classification of Reagents as Electrophiles and Nucleophiles. Acids and Bases
Chemistry LibreTexts - Structural and Solvent Effects in SN Reactions
Chemistry LibreTexts - Elimination Reactions
Good place to start.
Chemistry LibreTexts - Mechanisms of Nucleophilic Substitution ReactionsChemistry LibreTexts - Structural and Solvent Effects in SN Reactions
Chemistry LibreTexts - Elimination Reactions