Oh, sorry about that. I plan to add a tutorial once I have a bit more meat to the game. Milk raises the amount your employee produces when they orgasm, but also makes it harder for them to orgasm. Lube makes it easier for them to orgasm by making your clicks fill the meter faster. Porn adds a multiplier to produced fluid but doesn't impact how easy or hard it is for your employee to orgasm. All upgrades increase idle fluid generation by a small amount. Also, the further to the right an employee is, (or, if it's simpler to think of it this way, the more the employee cost you) the higher their base fluid production is, and the more idle fluid generation you get from their upgrades.