I have dipped one level in wizard to get familiar.
Normally I am Ivestigator and have Alchemy.
Does Share spells allows me to share personal extracts (with target of "You") with my familiar?
Technically, no. Extracts are not spells.
However, the Infusion alchemist discovery (which the investigator can take as an investigator talent) lets anyone use an extract with the range of personal. So, take the discovery and pass out extracts of shield to the other members of the party...
Share spell allows you to do two things. The first allows you to cast a spell on the familiar with a target of you as a touch spell. The second is it allows you to cast a spell on the familiar even if the spell does not work on the familiar’s type. Extracts act as spells except they can normally only be cast on the alchemist himself. Many of the spells that the extract duplicates already meet those conditions, but still cannot be used on anyone else unless you have the infusion discovery. This means that even with share spell you would still need the infusion discovery to affect your familiar.