已知等比数列\(\{a_{n}\}\)的公比\(q\neq 1\)，前\(n\)项和为\(S_{n}\)，\(a_{1}+a_{3}= \dfrac {S_{4}}{S_{2}}\)，\(a_{1}-1\)，\(a_{2}-1\)，\(a_{3}-1\)分别是一个等差数列的第\(1\)项，第\(2\)项，第\(5\)项．
\((\)Ⅰ\()\)求数列\(\{a_{n}\}\)的通项公式；
\((\)Ⅱ\()\)设\(b_{n}=a_{n}\lg a_{n}\)，求数列\(\{b_{n}\}\)的前\(n\)项和\(T_{n}\)．