Since you'll be coming down from NE, be sure to stop at Odell in Fort Collins. Odell is pretty much nationwide as far as distribution goes for their usual stuff, so nothing special there, but they always have a great selection of small batch brews exclusive to the taproom. And speaking of their taproom, it's one of the best I've seen. Just a great setup for both indoor and outdoor seating. Fort Collins has a metric crap-ton of breweries, but Odell is by far my favorite local spot due to the combination of great brews and an awesome seating setup. New Belgium is just down the street from Odell and has a very nice taproom as well, but I think Odell has better beer, or at least the selection is more varied. As mentioned above, Weldwerks is pretty good and has really started to make a name for itself up here, but will likely be a bit out of your way to make it over to the east side of Greeley. Right off Hwy 34 in Loveland (before you head up the canyon to Estes) are Verboten and Grimm Brothers, both great local breweries, then you could grab some lunch/dinner at Henry's Pub, which serves up great food and features local brews. All three of those are within a few blocks of each other in downtown Loveland. If you go up to Estes via Hwy 66 through Longmont and Lyons, you could hit Oskar Blues in Lyons, which also has great food and most excellent beer. The Lyons brew pub is their original location before they hit the big time.
In Estes Park, as mentioned above, Lumpy Ridge has pretty good beer, but the place is very, very small. I mean like room for about six people in the little taproom that once was a gas station office, but there is a fair amount of outdoor seating. Also in Estes is Rock Cut Brewery, which has some very good beer and a pretty decent tap room to sit and relax for a spell. I agree with the above poster that Estes Park Brewery isn't worth your time. The beer is so-so, and the food is very much forgettable. Smokin' Dave's BBQ, on the other hand is a great joint for food in Estes and they have a good tap list to go with it. Maybe hit Lumpy Ridge, then Rock Cut for a brew or two, then head over to Smokin' Dave's for Dinner. While you're in Estes, grab some breakfast at the Big Horn Restaurant.
On the other side of the divide, Palisade is the place for Colorado wine. There are some excellent wineries in Palisade and the area is small, so you could hit several in a couple hours. If you are at all looking for/interested in picking up some great Colorado wine, definitely stop at Hermosa, Maison La Belle Vie, DeBeque Canyon, and Veraison Wineries (if I were to pick only one, it would be Hermosa, hands down, followed by Maison La Belle Vie). If you like mead (and even if you don't think you like mead), check out Meadery of the Rockies, also in the town of Palisade. If it's beer you want, grab a brew and some lunch/dinner at Rock Slide Brewery in downtown Grand Junction. There's also Palisade Brewing, but it's rather mediocre and nothing to get too excited about... Rock Slide is much better with respect to both beer and food.