
this is by all means not comprehensive.
I played an elven or dwarven summoner ( I think )
points should be put in willpower and cunning at the start, I try to get up to 30 cunning before I invest in other skills.
fire imps are your friends, they can take down many if not all of the monsters you find.
So from the start I invest mainly in fire imp and war hound, these are your main stays, nothing else will do as much damage per equillibrium cost, though they can be good in their own rights. play cautiously through the whole game, if there is a corner summon a fire imp to the far edge to kill any monsters (only if you do not have a means of telepathy. if you are engaged in melee and can live a round, summon a fire imp in the distance and then retreat, they will target you, while your imp takes them down.
if you cant, run till you find a corridor and then summon a war hound behind you and then swatch places (drinking a heal potion as needed).
Ranged summons:
hydras are good for one thing mainly, worm control, beware that they may breathe on you if you are in the way. warpers are more like souped up imps that cost 4x as much or so. drakes are also more worm control, though they are a ranged summon that still packs a melee punch, beware that they may breathe on you if you are in the way. use if you need a healthy option to block and run.
Melee summons:
war hounds are your basic melee summons, nothing special. Jellies dont move, so they can be used to block a passage way and not chase down an enemy accidently. Minotaurs have confusion and higher hp. stone golems are tanks, but be wary about summoning them, as their ability will mess up the level, and can make it unplayable with an unlucky quake.
that said, I favor ranged above melee, with the total order being fire imp > war hound > fire drake > hydra > warper > stone golem > minotaur > jelly.
Utility summons:
turtles are nice to draw enemies away from you, combined with fire imps they can take down hoards of enemies. spiders can pin and poison enemies. spirits can heal.
I generally dont bother getting these though. I suppose with a spirit following you it might be ok, but the duration of any summon is not long enough to justify healing them.
augmenting summons:
very nice spells. you can increase the summoning duration, make you summons go into a rage, blow up a summon (only for three of them), and control them
summon duration increase is a must, though it is only for 5 more turns at max, but still that can be a life saver.
raging you summons is good too, as they do not level like other monsters and only have the stats from the summoning. this will give them more life and damage.
blowing up your summon is good if your summon is about to die, it only works for fire imp, ooze, and healing spirit though.
summon control is nice if you want to decide what your summon will do, it also increases the duration of your summons.
so all in all, make your summons go ahead unless you have a source of telepathy. then make them go ahead when needed.
summons take longer to level up because of the time duration of their summons, but they have an easier time because they dont have to fight (it still is a good idea to boost armor and defense in case you need it.
mage staffs dont really seem to help out with summons though (unless they are of wizardry), but then again, no other weapon is really necessary for them either.
I also invest in trap detection and disarming to reduce damage to summons from them, though keep in mind blast traps are *hard* to disarm.