About formulation of equation to solve in LBM

Generally we use non-dimensions form the NS equation for solving any problem.If I want to link macroscopic properties with that of lattice dimension how can I take care of that things in lattice dimension.If I want to solve flow through channel,I have to add extra forcing term in equilibrium function to have match of solution.How can we came to know about all these extra terms and other factors.Please suggest me.

Hi to you!
I want to suggest you some useful books to find your answer. At first i think the book written by Mohamad is so simple and useful for a beginner in Lattice Boltzmann. Below is the list of some book:
1-Lattice Boltzmann Method Fundamentals and Engineering Applications with Computer Codes 2011 by A. A. Mohamad.
2-Lattice Boltzmann Method and its Applications in Engineering by Zhaoli Guo and Chang Shu.
3-The Lattice Boltzmann Equation: For Fluid Dynamics and Beyond by Sauro Succi.

I have gone through the book u have suggested.but still i am having problem to simulate a flow through channel with addition of extra force term and its units.Should it is always beneficial to use dx=dt=1.0.And accordingly all other parameter must be set?