I have a pretty simple Excel Spreadsheet that I keep all of the part costs and supplier info on. I dont really use it to figure out what order to do things in, its just a nice way to keep track of the build cost and where I got everything from. If I need to send anything back its alot easier to look at than going through the reciepts. I probably should keep track of the hours I spend on it, but Im not looking to advertise that for any reason, so I just dont bother.