@craigo - get hold of brewmate (it's free www.brewmate.net).
Find a recipe that is in line with your tastes (recipedb is fantastic for this, or ask a respected AHB member whose beers you've tried).
Punch it in, ensuring that the quantity in the recipe equals the quantity on brewmate.
Then adjust the batch size to your system (I assume 12L, though I used to BIAB 25L on the stove in two pots). It will scale the recipe.
As others have said - BIAB is the ability to use slightly different equipment with a slightly different methodology to achieve similar results as a full-sized system (for less cost). Recipes aren't "made" for BIAB - just the brewing method adapted.
The idea is to extract sugary, malt-water from mashing the grain, boil said sugary malt water, and add hops in for bitterness at the appropriate interval. Then to pitch yeast at the correct temp. You do this properly (and assuming you sanitise and avoid infection), you make beer.
So a theoretical recipe of : 2kg of Pale Malt, 250g of Heritage Crystal, 100g of Caraaroma and 25g of CarafaIII, will produce the malt base for a 12L Irish Red (at 70% efficiency). You might choose to put 35g of EKG at 60 minutes boil, and Windsor yeast pitched at 22 degrees for a ferment temp of 19 degrees.
I could brew this on a RIMS, HERMS, Ghetto 3V, Braumeister, BIAB in an urn or on the stove. So long as I hit the numbers, what equipment I use isn't particularly relevant to the beer I wish to produce - as the beer produced will be basically the same, all other things being equal.
Get your process sorted and down pat, and know your system in detail.