If someone says a matter is Halal and another source says it a Haram then how do I decide which one is right? Can I pick whichever seems more logical to my mind?
No one has a right to pick in Islamic rules whatever he feels more logical for him. We must obey Allah even if our thinking based on our limited knowledge does not digest it. The orders of Allah are taken from the Prophet (SAWA) and his Holy Progeny Ahlul Bayt (AS). You need to follow the most highest scholar ( Marje' of Taqleed) to seek guidance.
Wassalam.