Ultracold polar molecules allow for investigation of quantum-state-controlled chemistry as well as strongly correlated many-body dynamics. After the first realization of polar molecules in the quantum regime, chemical reactions immediately became apparent in our KRb system. Upon obtaining a detailed understanding of the chemical reaction processes near absolute zero, we loaded our molecules in optical lattices that suppressed molecular reaction loss. In doing so, we were able to observe many-body spin dynamics between molecules pinned in a deep lattice, even though the filling fraction of the molecules was only ~5%. We have recently performed a thorough investigation of the molecule creation process in an optical lattice, and consequently improved our filling fraction to ~30% by preparing and overlapping Mott and band insulators of the initial atomic gases. This improvement realizes a fully connected quantum gas of polar molecules for the investigation of non-equilibrium, many-body spin dynamics. More recently, we switched to a second generation KRb apparatus that will allow application of large, stable electric fields as well as high-resolution addressing and detection of polar molecules in optical lattices. I will present our work on molecule creation in a three-dimensional optical lattice and the corresponding increase in the molecular filling fraction, as well as the status and direction of the second generation apparatus.