The first matter for you to conclude is to agree the terms of a shareholder agreement between the two founders. This shareholders agreement should govern the management of all significant governance matters. Without this you will subject to the constitution documents of the company and local company company law. This is a standard type of agreement that any decent corporate lawyer will be able to advise you on.

As the voting shares are held equally, then no major changes will be able to be made without both founders agreeing to the changes. The non-voting shares (assuming all other terms are the same) will have equal rights to financial returns (dividends and liquidation rights), but will not be able to participate in voting issues. In simple terms, you will have an equal say in the running of the company with your co-founder, but will receive 25% of the returns, while they receive 75%.