So this is just how I play Shyvana. Nothing special I realize, I just need feedback on how my guide fairs against your superior knowledge of this champion. Good, bad and the ugly comments are appreciated.

Pros:

Good at Burst DPS
Quick jungle clearing
Can become tanky when built
Ultimate is good for condensing enemies

Cons:

No form of CC to keep enemies away
Can be CCed and brought down easily

For runes I have your standard build (in my eyes that is)

For Marks: Greater Mark of Desolation x9
For Seals: Greater Seal of Armor x9
For Glyphs: Greater Glyph of Magic Resist x9
For Quintessence Greater Quintessence of Attack Damage x1 Greater Quintessence of Desolation x2

Sometimes I run either Greater Quintessence of Desolation x1 and Greater Quintessence of Life Steal x2

or

Greater Quintessence of Attack Damage x3

I feel the armor pen allows for Shyvana to breeze through jungle and gank easier with all the armor pen stacked alongside her Flame Breath.

For masteries I take 21/9/0 taking all the AD aspects in the tree. Shyvana in the jungle longer without backing. Fifth tier I take Sunder as said before, add in more Armor Pen to do more damage. Finally, last tier I take Executioner .

In the defense tree I take Summoner's Resolver, Resistance , Hardiness and Tough Skin (for jungling purposes). On the third tier I take Bladed Armor Just to reflect a small amount of damage to jungle creeps to make it go smoother.

To start off I take Vampiric Specter. After that, depending on gold or ganks, I grab a Cloth Armor, Boots or both. If you can pull off a successful gank, I try to rush the Wriggle's Lantern early so I can ward Dragon or top river so at least one lane won't get ganked so easily. Wit's End is my next purchase, to give me that Attack speed that is needed for ganking as well as the small shred in HP to add in for damage, plus the Magic Resist is useful. From here you can build your Trinity Force. It's all depending on the game but usually I buy Phage first and then Zeal and finally Sheen to finish off the Trinity Force.

I consider the above my core build. The rest depends on team composition and how I fair in kills and gold. Below are some of the items I usually purchase.

Situational Items:

Warmog's Armor
Atma's Impaler
Youmuu's Ghostblade
Thornmail
Guardian Angel

I start off with Burnout to clear creeps faster in AoE, plus the speed boost makes it a little easier to clear faster, I max this second. I get a point in Twin Bite and max it first for optimal damage output. With Flame Breath I pick up a point at level 4 and leave it till last to max because you get the same amount of armor pen (15%) at every level. For my ultimate, I pick up in the appropriate levels; 6, 11 and 16.

For jungling, I star off with red, clear wraiths and then wolves. I usually back grab level 1 boots or Cloth Armor. From there I pick up blue and make my way to Top or Mid lane (depending on necessity). I invade the enemy jungle when I know they aren't near it. Kill wraiths and leave a small one, or kill the big golum and leave the small one.

I'm very aware of Dragon and timers, so I try to cut it clean with Red Buff, Blue Buff, Dragon and Baron.