To give us an idea of the overall feeling of your brand, let us know which styles you lean towards
looking for a small neat 3D logo (similar to the example I uploaded) The name of the company will need to appear below, in a simple lower case font - think Neue Helvetica / Myriad or the like. The logo can incorporate letters (S and a 7) or similar. For obvious reasons the use of S and S together is a no go. Lets not even go there. Eventually the logo may be represented without the words "serial 7" below. But thats after (if) brand recognition kicks in. Ask as many questions as you want - I'll try and give as much detail as I can, but essentially Im open to all suggestions.
BTW its an online training product targeted at the corporate market, so no "education / uni / school" iconography.