There's already a lot of good advice on this topic, but I'll add a bit more.
Worm harvest 
can get to be a nasty token producer late game, as well as
orochi hatchery 
. You want repeatable token production, not 1 time use spells (with a few exceptions). For example,
sprout swarm 
is much better than
scatter the seeds 
. Other tutor effects you might consider could be
brutalizer exarch 
and
rune-scarred demon 
. With a 100 card deck full of singletons, it's handy to find the exact card you need, when you need it. Also, games tend to go long in commander, so the graveyard gets quite thick. Simple cards like
rise from the grave 
can often get you the best creature in either player's deck. Mana fixing is a must;
cultivate 
or
kodama's reach 
help immensly. There are plenty of other options both in and outside of green that you might like better, however. Finally, on a side note, the core set titans are very versatile and should be considered in your list.
Since noone else has directly pointed this out, i'll help sort through cards that should NOT be on your list. Creatures like cunning sparkmage, putrid leech and ember hauler have very small effects, and arent worth a card in a commander setting. They are quickly outclassed by later threats, and the damage they might get in before then is negligable compared to the 40 life starting total. Small effects like the quest for pure flame and pyroclasm arent worth a slot in your deck either; the quest only double damage from 1 source, but a token deck focuses on overruning the opponent with multiple different creatures. Another token producer would be better. Pyroclasm is an anti token card, so it makes no sense to include it in a token deck. Hope this helps!
