Where I find that GQ is good is for the shirt colors and the tie colors, not so much for cut, which as the PP said, tends to be overly trendy and probably photographed on a man with a 28 inch waist. However, those photos will teach you how to mix shirt and tie patterns.
DH actually buys most of his suits at Syms. He spends an average of $2500 per year on one shopping trip, and for that he normally gets around 6 suits, then spends an extra $75 per to have them tailored properly. (Because Syms is a discounter they don't offer full-service tailoring, but in the end it still costs a lot less because their avg. price per suit is closer to $300 than $600.) Syms does tend to carry a lot of obscure Italian brands, but the quality on them is usually very good. (The trousers tend to be cut small, though; never buy an Italian suit without trying on the trousers!) Of course, Syms also carries some cheap brands that we steer clear of; you just have to know your labels. (Suits do wear out eventually if you are wearing them every single day of the week, especially the trousers, now that suits are not sold with 2 pr. the way they were 50 years ago. DH has about 15 at any given time, and he wears them in careful rotation to minimize the stress of dry-cleaning on the fabric. Most of them last him about 4 years before they need to be replaced.)
If you watch sales at Land's End you can get some very nice shirts at a good price, and also decent conservative ties. Trust me, a LOT of lawyers buy their shirts and ties at Land's End; our county courthouse could pass for a catalog show. I got DH a half-dozen of their "paintbrush" buttondowns a few weeks ago when they went on sale for $20 each.
Shirts have their details, too. The first is cut: traditional or the more close-fitted trim. Next is collar: Button-downs are a tad on the casual side, but men who travel for business (or who don't like buying two sets of shirts) tend to favor them because they can also be worn dressed-down after hours without looking too formal. The straight collar is the most traditional, but the spread collar is a bit more popular now with younger men and men who want to look a bit less like their grandfathers. This site that makes custom shirts illustrates the most popular collar styles and comments on what face shape they best compliment. (A "standard point" on this site is what most mfrs. call a straight collar.)
http://www.bestcustomshirt.com/How-to-Choose-a-Dress-Shirt-Collar.asp
Shirts also have the issue of how the back yoke is cut (one piece or two), and whether or not there are back pleats and which kind (center pleat is more traditional in the US.) It is possible to have quite a few different cuff styles, but most ready-to-wear dress shirts sold in the US have either a single-button barrel cuff or a french cuff. Generally speaking, French cuffs are for men with slightly flashier style, because they require cufflinks.
As to shirt color, I know a LOT of attorneys who won't wear anything other than white or pale blue. However, French blue is only a little out of the ordinary, and looks great on guys with blue eyes, but it's harder to match with a suit. The next most popular color is very pale pink; it is a very flattering color on most people, and looks GREAT with a grey suit. DH has a rather ruddy complexion, and he likes ivory shirts for that reason; they tone it down better than white, though ivory is a tad unusual. He recently bought a pale purple shirt that caused a bit of a sensation at the courthouse, but it looks great on him. He also likes very pale pearl grey (what can I say? For a lawyer he's a bit of a rebel.
He also occasionally wears Mickey ties if he doesn't have court that day, but only the ones that are "hidden Mickeys" -- the sort that you have to look at very closely in order to see them. Most folks never notice it.)
You really don't see many patterned shirts in law offices around here; decorative weaves are about as far as they tend to go in that direction. (Things like single-color herringbone patterns and birdseye, for instance.) However, if your DH is not an attorney they won't expect him to dress as conservatively as they do -- he can go a bit more imaginative with his shirts and ties. Attorneys tend to go very conservative in their style because you never know when a judge may rule against you because he thinks that your shirt or your tie is too casual for his courtroom.
One last thing: an overcoat. He needs to buy a decent long one to wear with the suits. If he will be expected to attend evening events at all he'll need to invest in a black wool topcoat, but if he will strictly be dealing with office wear he can get away with a nice black thermal-lined trench or balmacaan. Having the raincoat function in the coat is helpful if he will be traveling.