So, you just have to look at peoples' records, their sources, their sources' records, at how plausible it is that their sources are what they claim they are, and decide what, if anything, you want to believe. Assuming that you don't just curl up into a ball for a few days, and ignore the war completely, which may be the more rational course of action.
An example: There's a site I have seen cited with interest on several comment boards -- www.iraqwar.ru, some of whose reports are available in English, e.g., here; they claim to be based on both a distillation of open source intelligence (i.e., journalistic and other reports), and selective leaks from Russian intelligence. Or not so selective -- many reports are attributed to communications intercepts from American and British units in the field, and the report I linked to actually goes further, claiming to summarize meetings at the Pentagon, and even an "online meeting" including, among others, Rumsfeld and the Joint Chiefs of Staff. Worrisome as it is to suppose that Russian intelligence could actually listen in on that sort of "online meeting", whatever that means, it is difficult to believe that anyone in Russia who had possession of those sorts of intercepts would allow them to be posted on a public web site -- translated back into English, no less.
Or at least, you have to hope. Because if those intercepts are even close to accurate, we are in deep, deep trouble.