I thought the first 2 answers are spot-on. We used the Portfolio Collection extensively during our first trip to CT last year. This is the Portfolio website.
http://portfoliocollection.com/static/misc/ord er.aspx
Though it says you have to pay for the booklets, I think this is just to prevent timewasters - we didn't pay for them.
Armed with the books we then emailed a whole series of bookings to these B&Bs. You need to appeciate that B&B in SA is not the same as in the UK. These places are not people offering an odd spare room for a few quid at the weekends - these are proper businesses run by homeowners, many in substatial grounds. On average B&Bs seem to have 5-6 rooms to let - they are like mini-hotels without the evening meal option. Prices by UK standards due to cheap labour and weak Rand are incredibly good value - we were paying around 800 Rand per doubleroom - about �65. Some of these places were palacial, with pools and all sorts.