Any costs that you incurred to set up your corporation are converted to stock or paid-in capital. The total represents your basis in the company.
Record this on the Balance Sheet as Shareholders Equity, with an equal entry under Business Expenses. You may expense up to $5,000 in start-up expenses in the year your business begins. Any amount over $5,000 becomes an intangible asset that is amortized over 180 months.
See this link for more information: IRS Pub 535 Business Start-Up and Organizational Costs
On the other hand, if your corporation invested in a startup company, you would report this on the Balance Sheet as a long-term asset (not for depreciation).
If you elect to expense up to $5,000 of expenses, you would debit expenses credit cash (or A/P).
For the amount (if any) over $5,000 that may be amortizable, you would debit an asset account and credit cash. Then when you amortize the costs, you would debit amortization expense and credit accumulated amortization.
There are some costs that may not be expensed or amortized...these deal with the corporate stock itself. You would debit an asset account, such as intangibles or stock cost, and credit cash.
These cost do not increase your basis in the stock you purchased or received in exchange for contributions of cash or other property.