Ok here is a back of the envelope briefing.
Take a human, any human, take these two feats at the beginning of character creation.
Natural Talent (lets say you get Telepathy sphere)
Psionic Training(under training at the psionic institute you are able to pick up Awareness and Clairvoyance)
So you start out in the Objects of the Mind Psionicist class you have Telepathy, Clairvoyance and Awareness.
At first level you get no extra feats.
Each sphere is developed like a class skill, which means you allocate your skill points like this
Telepathy 4
Clairvoyance 4
Awareness 4
Remember you can not have a skill level greater than your character level plus 3. That includes bonuses from attributes too. So at first level the highest skill level you can have is 4th.
As you advance in levels you increase the sphere's just like they are a class skill. Hint Hint always use every skill point to increase these.
This means that all talent under each sphere lets say Telepathy, you can use. Under Telepathy sphere you can use:
Rank
Shield 1
Life Detection 1
Telempathy 2
Read Surface Thoughts 4
The psionicist class is different than the character who just get Psi Training why?
Well a Psi only trained pc would need a feat for Telepathy and a feat for each talent under telepathy.
Back to the Psionicist, at 5th level you gain another sphere of psionics, in this case lets say Telekinesis. The feats up to this level you use on feats that are not class restricted but you can not use them to get more spheres of psionic talents etc.
At 9th level you gain another sphere of psionics in this case Teleportation.
At 13th level since you have all the psionic spheres you can use that for another non class restricted feat.
The Psionicist class gets more spheres/talents than a just Psi trained pc.
Let me know if you still need assistance.
Sinbad Sam