August is off-season for the Phoenix-metro area, so the rates are generally pretty good.
Scottsdale is actually quite large, covering a distance of over 20 miles from North to South. Knowing where your DH is going to be will likely help you plan which location would be best.
The Hyatt Regency Gainey Ranch is more 'central' & east and is a wonderful hotel (I got married there years ago). There are other newer hotels as well.
JW Marriott's Camelback Inn is in the heart of Paradise Valley up against the mountain (Mummy Mountain). It is and has always been one of the top Marriott resorts in the US. To the North, they've added the JW Marroitt at Desert Ridge. That is North of the 101, and is near the Desert Ridge marketplace (outdoors, so will be hot to 'mill around').
Sanctuary is a boutique hotel up against Camelback Mountain (on opposite side of street in Paradise Valley near Camelback Inn.
Down the Street is the Intercontinental's Monteleucia.
A great resource is the Scottsdale Convention & Visitor Bureau -
http://www.scottsdalecvb.com/hotels/resorts/index.cfm?sfilter=ALL&efilter=ALL&startrow=26
There are 70+ hotels in Scottsdale and most would be a good option. Knowing, though, where your DH will need to be will be helpful since you're looking at a very large area and if you're at one end of Scottsdale (say Desert Ridge) and he's down by Old Town he'll have about a 40 minute drive (we do not have an easy highway to get through Scottsdale and we have photo radar!).
Hope this is helpful! You'll love it here in August. The weather is hot but nice in the early AM and evenings. We have CVS, Walgreens, Target and Walmart so just make a list of a few things (sunscreen!) and get it here.
If you have any other questions, let us Arizonan's know!