Contractor Work

[BengalHawk62]

For those of you in the know, how do contractors get paid?  We are starting an addition/remodel to our house this weekend.  Our contractor told us the basement digging guys are going to be at our house on Monday to start digging but that he, the contractor, needs $2k upfront to get "started".  What exactly does that mean? Is that normal?  I guess this is the part where we need to keep our receipts through out the project handy.  Plus the bank requires us to get "lien waivers" from everyone we are paying through out the project. Don't get me wrong, I fully trust this guy, its just that I don't know how this whole construction thing works yet.  What are some of your experiences regarding contractors and home remodels.  Thanks for any advice in advance.