Minecraft wiki entry for Defeating_a_village_raid, associated text: Some Ender pearls for quick escapes.
Milk, to remove negative status effects from the witches that could affect your perfomance.
Negative Splash potions, to hinder groups of raiders.
Regeneration or healing potions to recover quickly. If you have iron golems when you're hurt go to the iron golem and throw a healing splash potion at your feet, healing both you and the iron golem so you can heal two mobs at the cost of one potion.
Golden apples to tank enemy attacks and provide a swift healing cover.
Cobwebs to trap raiders.
A Lava Bucket for quickly eliminating Ravagers and other mobs (excluding witches, which drink Fire resistance potions).
Some dirt blocks (you can use any block you want) to pillar jump and attack melee raiders easier (this is not recommended with pillagers, as they can shoot you off the pillar with their crossbow).
A boat or minecart to trap any melee raiders (preferably vindicators or ravagers) to trap them so you can kill them without them chasing you (you can also do this with pillagers, but try to block or dodge the arrows).