This page lists all perks in Fallout.
Perks in Fallout are acquired every three levels (four with the Skilled trait), with the first available at level 3 (4). With the max level set at 21, the player can choose seven perks (five with the trait) out of a total of 53.
Some perks have multiple ranks, with stacking benefits (all benefits are listed per-level). It is possible to obtain perks that the player's character doesn't qualify for by the use of temporary stat improving chems before the selection menu (i.e. a character with 4 Intelligence can use Mentats to select the Educated perk, which requires 6 Intelligence).