HARRISBURG - Gov. Ed Rendell signed a $26.1 billion state budget early Sunday morning that would boost state spending by almost 6 percent, provide large increases for education and create a new children’s health insurance program. Rendell signed it after a marathon day in the state Legislature, as lawmakers worked to finalize the spending plan for the fiscal year that began Saturday. ``This is a terrific budget,’’ Rendell told reporters after it had passed, but before he had received the bill to sign it. ``It is a budget that accomplishes a great deal.’’ The budget ``is a full percentage point lower than the average increase in the 41 budgets that have been approved by legislatures and signed by governors around the United States of America,’’ Rendell said.