I'm assuming the link loaded, right? They start on page 6 of 18 and continue on to page 9.
Everything listed as blue: Spell Focus, Spell Specialization, Greater Spell Focus, Intensified Spell, Quicken Spell, Dazing Spell, Spell Perfection, Improved Initiative, Improved Familiar, Toughness, Spell Penetration, Greater Spell Penetration, Additional Traits.
Listed as Green: Sicken Spell, Empower Spell, Maximize Spell
Listed as Yellow: Persistent Spell, Rime Spell, Quick Draw
Some of them change in value as certain situations change. For instance, Additional Traits is blue only if it's your only way to get a specific trait. Each of them on the list comes with a great explanation as to why he thinks you should get them. You should really read those in order to decide if his reasoning for each is pertinent in your situation.
If you're planning to truly focus on a particular element, then adding in elemental focus and greater elemental focus can further boost your save DCs. They're not mentioned in the guide because he advocates against focusing, but if you're making a draconic lightning blaster, you might find them useful.