MOGADISHU, Jan 8 (Reuters) - Somali President Abdullahi Yusuf entered the capital Mogadishu on Monday for the first time since taking office in late 2004, a government source said. "The president has arrived in Mogadishu. He is now resting at Nasa Hablod hotel. We are now preparing his house in Villa Somalia, where he will be staying," a government source who declined to be named, told Reuters.