Not having it, I can't say whether there's an 'official' way of doing things or not. I can, however, point you to
my way, which allows you to summon monsters by challenge rating (although everyone does that). It also has guidelines for summoning large numbers of smaller monsters, creating custom summon lists, and summoning undead if you're a necromancer.
It's not perfect. One thing I neglected while putting it together was the fact that some summonable creatures can throw out spells at will, sometimes higher level than the spell that summons them. I suggest the following rule of thumb for summoning creatures: Either use its CR according to whatever way you use, or use the highest-level instant non-personal spell level plus one, whichever is higher, to figure which summon level it is. F'rexample, a Vrock demon can cast Mass Charm (lvl 8), so would automatically be lvl 9 to summon (CR 13 also qualifies it); a Hellcat devil is CR 7, and has no spell-like abilities, so it's just lvl 6 to summon (by my method).
I hope this comes in handy until someone points out whether they've actually updated the lists...