More or less, psionics falls on two basic principles:
ONE) You no longer have spell slots, which is both good and bad. Good because you can allocate how your powers are manifested, bad because you no longer have the backbone of knowing you have x number of resources to fall back on.
TWO) Psionic focus which controls a lot of your psionic based feats and requires ample timing to not be wasted and to not put you in a position where you have to accept death.
You have to get a hang of those two mechanics before you should even bother looking at disciplines.
Disciplines work almost exactly like wizard specialization schools. Unless you have a really good grasp on what you wanna do, stick with the basics.
Hey! So psionics has been a hot topic lately, and its really rough to give advice without being told what specifically you need help with. Luckily, you can always get the book and there is quiet a bit of OGL material for pathfinder and 3.5. You can start by reading how powers work here. If you get confused on a particular topic, you can always post on the dreamscarred presses forum or here, lots of helpful people. Its also not an uncommon topic, so a lot of times running a quick search can find you a quick answer.
A psion is a caster kinda guy, 1/2 BAB and gets a ton of power points and powers known. You get bonus power points based on your level and casting stat, don't forget to add that in.(Chart here) When you cast you get to spend points to cast the power, and you can spend additional points to augment your power and improve it. One of the things that make Psionics awesome is this, because gives you control over what you cast and how much power you want to use or reserve in a moment and it means some of those powers can stick around longer and be useful even into the higher levels.
Anyways, goodluck, hope you fun.
Fun thing about the new Psionic stuff is there are 10 classes to pick from covering a really wide range of ideas of possibilities.
The Psion is pretty much your Wizard. He's the guy who has devoted himself to study and mastery of the mind.
but he's not you only option. Dreamscarred has added some fun new classes like the Vitalist who manipulates the party's lifeforce to heal them or the Tactician who links his party together telepathically for combat. Both fit really nicely with the idea of a Telepathic character.
have the books, reading it doesnt say much for experience vs theory.Get the book. Paizo sells it and so do others... Psionics Unleashed by Dreamscarred.
Because we're not going to be able to teach you the system in one post... or a few dozen.
The experience will vary depending on how the GM runs things. With that said, if you can run a caster then you can run a psion. Instead of spells slots they use power points, and you have to manage them carefully in most campaigns. You might be tempted to max a power out, but doing so may leave you out of power points so dont be afraid to use a crossbow if the battle is well in hand, especially at low levels.
With that aside you might want to ask specific questions.
mainly feats...i dont know whats good and whats not. i read them, but a lot either seem far too narrow of a scope to bother with, or im not clear on how they benefit me.
sorta like how spring attack or vital strike might seem good, but are trap feats.
Talented, Overchannel, Power Penetration(similar to spell penetration),
Persistent Power,Piercing Power(for this one it depends on how much SR/PR you will have to deal with), Craft Wondrous Item(saves money), Unconditional Power(situation so not a must have but if you ever need it, you will be glad you had it), improved initiative...Another of looking at it is like this--->Look for the psionic version of a feat that you would give to a caster.