There are six types of actions.
Not an Action (NaA)- this effectivly takes no time.
Free Action (FA)- can be performed while taking another action
Partial Action (PA)- part of a standard action
Move Equivolent Action (MEA)- takes the place of movement or a partial action
Standard Action (SA)- You can perform this action and still move your standard movement in a round
Full-Round Action (FRA)- Consumes the entire round.
Here are the valid combinations:
NaA - can be performed infinatly
FA + PA + PA + PA + PA
FA + PA + PA + MEA/SA
FA + MEA/SA + MEA/SA
MEA/SA + MEA/SA
FA + FRA
FRA
Here are the standard combat actions by category
Free Action: Cast a Quickened Spell, Cease Concentration on a Spell, Change form, Drop an Item, Drop to the Floor, Make Spellcraft check on counterspell attempt, Prepare Spell components to cast a spell, Speak, Use an extrodinary ability,
Partial Action: Start full round action
Move Equivolent Action: climb, control a frightened mount, draw a weapon, load a hand crossbow, load a light crossbow, loose a shield, mount or dismount, move a heavy object, open a door, pick up an item, ready a shield, rerieve a stored item, sheathe a weapon, stand up from prone
Standard Action: Activate magic item, Aid another, Attack melee, Attack ranged, Bull Rush, Cast a Spell, Change form (shapeshifter), Concentrate to maintain or redirect a spell, Dismiss a spell, Feint, Heal a dying friend, over run, ready, Ready to interupt a spell caster, readying to counterspell, rebuke undead, strike a weapon, strike an object, total defense, turn undead, use a 1 action (most) skill, use extraordinary ability, use spell-like ability, use supernatural ability, use touch spell on one target
Full Round Action: Cast a full-round spell, climb, change form (polymorph self), charge, coupe de gras, dive attack, double move, Escape from a net, Extinguish flames, Full attack, Light a torch, Load a heavy crossbow, Load a repeating crossbow, Lock or Unlock weapon in locked gauntlet, Prepare to throw oil, Refocus (no move), Run, Throw a two handed weapon with one hand, User a 1 round skill, User a touch spell on up to six friends,
Hope this helps.