New homeowner, Contract work, and tax witholdings

How do I file for a tax exemption as a new homeowner? Also, I do some consulting as a sole proprietor, and hoping to shift my contracts to my LLC. What are ways I can mitigate the amount of taxes owed.

 

Also, I'm a single woman without dependents and find tax season to be incredibly difficult. How do I ensure my employer is withholding enough from my paychecks so I'm not asked to pay such high amounts during tax time.