NOTE: This build is a bit tweaked toward a PvP server as that is the kind of server that I play on, so you might need to tweak it a little bit for PvE. I've also assumed that you'll be soloing right up until 60 (if you start doing high end instances before then you'll probably be forced to re-spec Resto like the rest of us are).

Also bear in mind this sequence may have a few steps which look pointless but in fact those steps are in there to jump to the next useful talent.

Lvl 10 - Nature's Grasp - rank 1/1
This is for the sole reason that it's an EXCELLENT backup when you get ganked. Hammer it on and RUN (if you can't heal and sort them out)

Lvl 11 - Lvl 15 - Ferocity - rank 5/5
As we're going to be concentrating on levelling as fast as possible we're heading up the Feral Tree as fast as possible. Ferocity is a better choice than Feral Aggression as FE is more for protection, whereas Ferocity helps with attacking.

Lvl 16 - Lvl 20 - Feral Instinct - rank 5/5 OR Thick Hide - rank 5/5
This is entirely based on your style of play. If you enjoy sneaking up behind enemies in cat form and then shredding them up go for Feral Instinct. If you prefer to just dive straight in and not bother with stealth go for Thick Hide.

Lvl 21 - Lvl 23 - Sharpened Claws - rank 3/3
6% Crit chance increase. Nice little boost for your feral fighting.

Lvl 24 - Feral Charge - rank 1/1
Great for duels, 1v1 PvP and stopping mobs tagging other ones.

Lvl 25 - Feline Swiftness - rank 1/2
Nothing really significant but a little extra speed in cat form.

Lvl 26 - Lvl 28 - Predatory Strikes - rank 3/3
Attack Power increased by 150% of your level. Now that's a bit better huh?