Main differences between 3.5 and Pathfinder?

[Socksy]

I'm a 3.5 player, and my boyfriend is getting me to play his Pathfinder game. What's different, other than skills and feats, larger HD, and that weird thing where I get an extra HP/PP/Skill point for being an Elan taking Psion levels?

Apparently I have Mind Link as a... Psion cantrip thing? How often can I use that? Int 19, Wis 12, Cha 7 if those are relevant.

Are magic item costs and/or WBL different? She's fifth level.

Will I have to change her powers known or are they the same as 3.5?

[Alent]

I can't speak to the psionics, but assuming it inherits the "As (Spell)" rules... quite a few spells changed, you'd be wise to look through your powers list on the PFSRD in depth.

Reading up on the bestiary would also be a good idea. In exchange for extra immunities, many 3.5 imported creatures have reduced (sometimes drastically reduced) hit dice. Quite a few things you face will be easier to kill, but immune to various status effects.

[Drachasor]

3.5 Core Items kept the same costs.

The WBL is roughly the same.

There were a ton of little changes to rules, feats, and spells. It's like the 3.0->3.5 change...perhaps a bit worse. You should assume nothing is exactly the same and always double check until you know for sure how PF handles it. Heck, sometimes they just changed the "intention" behind the text and hence how it works. It's kind of a mess, really. Even more so if you want to incorporate all the FAQratta, Blogratta and so forth (and it is really of questionable value) -- the PFSRD includes all that which is both good and bad.

The PFSRD will have all of the information you want. Do a search if you can't find something.

[BWR]

The major changes are in classes and skills.

Things still work similarly enough that you can play PF with tons of 3.5 rules isntead of the PF rules and never notice it. As others have said, it's best to check on everything just to make sure.

Otherwise, this list (http://www.giantitp.com/forums/showthread.php?t=136890)might be helpful. I don't acutally agree with all of the OP's conclusions, but the changes are on a handy list.

[Drachasor]

The major changes are in classes and skills.

Things still work similarly enough that you can play PF with tons of 3.5 rules isntead of the PF rules and never notice it. As others have said, it's best to check on everything just to make sure.

Otherwise, this list (http://www.giantitp.com/forums/showthread.php?t=136890)might be helpful.

Note that list isn't remotely complete. Summon Nature's Ally got a big nerf for instance. Summon Monster got a huge buff. Animal Growth got massively nerfed (probably should have had its level lowered or duration upped, but they didn't). Tons of feats got changed. +3 to +5 enhancement bonuses on magic items now penetrate more types of Damage Reduction. There are odd tweaks here and there in the combat rules. This is just touching the surface.

And then some stuff didn't get changed or old rules didn't carry over properly. If you make an Acrobatics check on Grease, are you flat-footed? The rules don't say you are, but Grease indicates you are. Part of the 3.5 rules for Balance got trimmed in the skill merge and who knows what the intent is? Similarly, the rules for mounts needing to be one size category got trimmed out...probably by accident. There are some real messes here and there.

You really have to read anything you use again. The changes are just too numerous to easily list.

[TuggyNE]

There were a ton of little changes to rules, feats, and spells. It's like the 3.0->3.5 change...perhaps a bit worse. You should assume nothing is exactly the same and always double check until you know for sure how PF handles it. Heck, sometimes they just changed the "intention" behind the text and hence how it works. It's kind of a mess, really. Even more so if you want to incorporate all the FAQratta, Blogratta and so forth (and it is really of questionable value) -- the PFSRD includes all that which is both good and bad.

Sadly, this is correct. The main difference, in short, is a ton of tiny differences.

It's perhaps most aggravating for one such as myself, who is intimately acquainted with the 3.5 SRD, but often struggles to find a rule I know should be there somewhere in either of PF's.