You've picked a really popular section of the PCT, so should anything happen (Lord forbid, and you seem to be well-prepared), there will soon be someone coming along.
Also, you've picked the best window for dry weather (last 2 weeks of July and 1st 2 weeks of August). That doesn't mean it won't rain, but you have by far the best chance for good weather, and any rain will be brief--the chances of a 3-day soaker are almost non-existent. Note, though, that if you are not prepared for rain, it probably will rain, while if you take lots of wet weather gear, it will be dry the whole time! The last week of July should also be the peak time for wildflowers. However, be prepared for mosquitoes!
The only problem might come if the Kendall Katwalk just north of Snoqualmie Pass hasn't melted out. Usually it's fine by mid-July. While we haven't had quite as much snow as last year, we have had a similar cold and wet spring, as you probably already know. However, the weather seems to have warmed up, so if current conditions persist, it will not be a problem. You can keep track of snow conditions on the Katwalk by following trip reports on www.nwhikers.net. If the snow is late in melting, you may also have some problems with stream fords below Mt. Daniel. If it's too bad, you can detour by dropping down to Fish "Lake" (more like swamp) on the Cle Elum River and following the Hyas Lake trail to Deception Pass.
USGS maps will show topography but won't show the current route of the trail, while USFS maps don't show enough topographical detail. However, since you're following the PCT and not doing cross-country routes, the USFS map (either of that section of the PCT or of the Alpine Lakes Wilderness) should be sufficient. Or you could check out the Green Trails maps of that area. While I'm not normally a fan of REI, they do have a tremendous selection of maps, especially in their downtown Seattle store. It's worth a trip there just to take a look!