I'm quite experienced with AD/MS Exchange etc when it comes to a single AD domain. What I'm not sure about is how I "should" set up AD when taking over IT for several daughter companies of ours.
They all want the same basic services (AD, Exchange, Terminal Servers) etc. We probably have to separate them into isolated TS enviroments due to special applications being installed, but other than that I can't really see any reason to use subdomains in AD (it will require us to have much more DC's).
Are there anything I should be aware of before using a single domain for this? Are there benefits to child setups/trusts etc that I dont know about?