In this case, you need to write a remark about that circumstance on the Business Property Statement, or on an attachment to it. Also fill out Part III (Equipment Belonging To Others) of the form. If you own any small equipment, such as a printer, copier, etc., that you are using in the business, you should report these costs under Part II of the Business Property Statement and also Schedule A.
In a few states, you must take an additional step to make your company official: You must publish a simple notice in a local newspaper, stating that you intend to form an LLC. You are required to publish the notice several times over a period of weeks and then submit an "affidavit of publication" to the LLC filing office. Your local newspaper should be able to help you with this filing.
Where the equipment you use in your business was acquired as a gift, you may report your estimate of its current market value on the Business Property Statement (that is, what you think it would sell for in the open market place). Enter that estimated value in the most current year's cost line and add a note indicating that the entry is an estimate.