Chopicalqui is sometimes dubbed the easiest 6000 peak in the Cordillera Blanca, with good reason as its south-west ridge route is only rated around AD. This makes it very popular and it can be crowded at times. However, more than one party has been turned around by snow up to the chest on the last portions of the climb, and the route gets out of condition after each heavy snowfall.
Due to its proximity to the two Huascaran peaks, Chopicalqui can seem less significant than actual height would warrant, especially when seen from Huaraz. It is sometimes called the Eastern Huascaran summit.
The climb offers spectacular views of neighboring summits Huandoy, Chacraraju, Pisco and Huascaran, and most of the range is visible from the summit.
Chopicalqui is located in the center of the Cordillera Blanca. Most expeditions start in Huaraz (the "Chamonix of South America") and take some form of transportation to the town of Yuangay, on the foot of Huascaran. A dirt road will then take you to the Yanganuca lakes and finally to the trailhead for base camp, located on the bottom of the big pass, at the point where the river comes closest to the road.
Since this is on the way to the very popular Santa Cruz trek, transportation is cheap and easy to find. Collectivos make frequent trips and taxis can also be arranged.
It should be possible to find transportation back to the cities just by waiting on the side of the road and hailing passing vehicles, but it can be a bit of a gamble after 3pm. From Huaraz, you should count 2h to get to Yungay and 1h to the trailhead.
It is also possible to enter the valley from the east through the Portechuelo de Yanganuca. This is not really a practical option as the east side is very remote. It seems more likely that one would exit the valley through this pass to visit the less frequented regions to the east.
Chopicalqui is located inside the Huascaran national park. As of 2009, there was a 65 soles (~20$) entry fee, valid for 30 days. It is to be paid at the entrance of the park, shortly before the Yanganuca lakes, not in Huaraz.
There are also regulations saying that it is forbidden to climb in the park without a guide, but it is not always enforced. Being a member of an alpine club in your local country could also exempt you from this rule.
The climbing season runs from June to September, with July and August being considered the best times. After that, the rain season comes in and heavy snowfall is to be expected.
The Cordillera Blanca is one of the ranges with the best weather in the whole world, with a lot of consecutive high pressure days during the dry season, but fast changing conditions should of course not be underestimated.
Proper acclimatization is of course essential for a successful summit bid. A popular option is to climb neighboring and non-technical peak Pisco. Base camps are not shared but close enough to each other that it is possible to go to Chopicalqui BC directly on the way down from Pisco. Another option is to climb Yannapaccha, a slightly more difficult but much less crowded peak.
Camping is allowed anywhere in the park. Great care should be taken when drinking the water, as many animals are grazing, even at altitude. Iodine can also be difficult to find in Huaraz, so it could be worthwhile to bring some from home.
Regular camping gear can easily be rented or bought in Huaraz.
There are unfortunately no websites with up to date weather or mountain information, the easiest way to obtain that kind of information would probably be to call the casa de guias in Huaraz, or one of the most reputable agencies (Skyline, Andean Kingdom, Aventures Andines...).