Intelligence is very important in Afghanistan, and not much talked about because, well, the more the enemy knows how the foreign troops collect information, the more likely the bad guys will come up with better ways to hide their secrets. So here are some of the obvious methods, with details, the enemy hasn't sorted out yet, left suitably vague.
UAVs are particularly useful because they can observe an area constantly and stay out of range of enemy weapons. More UAVs are being equipped with equipment for listening in on wireless communications (SIGINT, or signals intelligence). This usually consists of listening in on enemy cell phone and radio conversations. One problem with SIGNINT is getting enough translators familiar with the local dialect. One useful solution for this is software that can pick out important conversations, so that a human translator can be called in to listen to the whole thing. The enemy in Afghanistan is particularly lax in their use of cell phones and other wireless devices (walkie-talkies and such). More experienced Taliban and al Qaeda leaders are forever hassling the young guys about this, but Afghan warriors tend not to pay attention. NATO trainers have the same problem with Afghan army and police recruits. The more attentive Taliban do attempt to use a lot of code words, which your intel people will have to try and quickly decode, or have the code in advance.
Another technique honed to perfection in Iraq is quick exploitation of information found after a bomb or missile strike on the enemy. Whenever possible, troops are rushed to the site to grab whatever documents, and survivors. There are specialists who can quickly check out the data and report it to an intel center that has huge databases and software that can plug in new information and quickly get a list of likely new targets. These are then promptly gone after. Do this right, and the friends and associates of the guys who just got blasted will get attacked or arrested before they even find out their buddies have been taken down.
The Special Forces and other special operations also have a lot of effective tricks for obtaining and quickly exploiting information. This is kept very secret for good reason, as the special operations troops work in small groups, and rely on stealth, secrecy and surprise to succeed and survive.