I have bought a computer, filing cabinet... for a new business. On my balance sheet and in my ledger they are listed as assets. However on my income statement they are expenses. My balance sheet is not balancing unless I keep the asset only in assets and do add them into expenses on my income statement (which affects the total equity).
My question is, where/how do I post start-up costs for equipment (which is also an asset)?

However on my income statement they are expenses.

THIS IS INCORRECT !!

Your Balance Sheet is not balancing because you are doing, what is known as double dipping.
a) Assets
b) Expenses

How do I post them? I believe in the journal and the ledger they are assets. But I thought they were expenses (because I bought them to run the business). Where dot hey fit in?

DEBIT Computer Account XXXX
DEBIT Filing Cabinet Account XXXX
CREDIT Capital (owners) Account XXXX

Being Computer and Filing Cabinet
brought into the business.