Spectre shoud be played in the SAFELANE.
She kinda needs a SUPPORT in lane.
Good SUPPORTS are: Warlock, Dazzle, Witch Doctor, Pugna, Ogre, Disruptor, Oracle, Phoenix, Omniknight
Maybe some more, but basicly a support with a HEAL is really nice for Spectre, since keeping you alive, while the enemy is hunting you down, will deal more and more DMG,
because of ur E-SPELL/DISPERSION !

THIS IS NOT THE ULTIMATE SPECTRE GUIDE!
Its just what I like to play.
Your CORE ITEM pretty much every game shoud be Radiance, but keep in mind the Sacred Relic cost 3800g, and while u farm for it, you will be relativly weak, compared to an enemy carry with same GPM, who actually
bought items for his gold.
So, what i like to do is building TANKY from start.
I go POWER TREADS instead of PHASE BOOTS, nearly everygame. They give you +200HP, 25 ATTACKSPEED and of course the possibility to TOGGLE them, for extra MANA/HP/DMG etc.
My second ITEM is a VANGUARD (+250HP,5.5HP-REGENERATION), again an ITEM to TANK-UP and later into the game u can UPGRADE it to an ABYSSAL BLADE (or maybe a Crimson Guard).