There are multiple "good tips" in this thread, however, it still comes down to a matter of "best fit". There are so many IT consulting companies out there that it is hard to know which is right for you. The basis of this posting is about fit. I am very versed in many different platforms, however: my posting is not about me. It is more about what I do (and what others in IT consulting "should" do). Certifications are not always worth their weight in gold. They do offer a certain amount of credibility (rightfully so). To me, they demonstrate a willingness on the part of the individual (or their company) to invest in that certification/title/prestige. For the most part, those that are certified have a level of competancy that rivals those that do not (there are exceptions). Most importantly is communication. Has the person or company that you have been (or will be) dealing with truly informed you of the positives and negatives? Can you convery your concerns, frustrations, and issues with them in a manner which is non-confrontational? While my strong suit is a Microsoft platform, there are alternatives that may be quite appropriate for a given business. My definition of communication, where IT is concerned, is:
what is your mission statement
how do I or would I like to do business
do I have remote/field employees
what kind of information do I house (yard/landscaping) information is not critical...security wise...your client's iformation that use your service and you store on your server or workstation IS.

Mantainance of one's server (any kind) is critical. If you are unable to do this, allbeit personal preference, training or stuborness, it has to be done. As all of the previous postings have stated, "Please make sure you know who is taking care of your network".

Sales individuals know one thing...sales. Engineers know networks and what their sales people sell (most of the time). Hopefully your "engineer" will be your guiding light and conduit.