All of the settings have an impact on either the amount of sugar, the amount of water, or the impact of hops on bitterness. If you use the equipment wizard, the program will walk you through the inputs needed to create a profile.
Some of these you will need to take a guess at and adjust as needed so that the profile and program give you results which are accurate to your measured results. There are some things you can do to gather initial information before starting the profile wizard. Get an accurate weight of the vessel you are intending to mash in. Fill you kettle with a known amount of water and boil it for 15 minutes, measure the residual amount of water and multiply by 4 to get an approximation of your boil off rate. Brew house efficiency is usually what throws most people off. For your first brew, you can estimate an efficiency of around 65% or 70%. Since the brew house efficiency is dependent upon your process losses and extraction of sugar from the grains, you will need to make adjustments after you make your first few brews to improve accuracy.
I also highly recommend making a measuring stick ti give you accurate volumes from your boil kettle and/or mash tun. I give a methodology for how I make an accurate measuring stick in this thread: http://www.beersmith.com/forum/index.php/topic,20873.0.html
Once you are ready to make your first brews using BeerSmith, there are a number of process measurements which will help with 'dialing in your system'. Accurate measurements of volumes into the mash tun, out of the mash tun (pre-boil volume), post boil volume, fermenter volume and trub/kettle losses. Gravity readings post mash and into the fermenter (or post boil). All of these readings will help in determining the critical specs which you can use to update your equipment profile. BeerSmith also gives you a calculated actual mash efficiency and brew house efficiency on the sessions tab once you add your measured data into this tab in the cells provided.
While this may seem daunting at first, the more care you take in getting accurate measurements, calculating actual losses, and feeding this info back into the program the better the program will work for you.
And feel free to ask for help if you need guidance on making sense of your data!
