What CAD product are you planning to utilize? They each have their own way of template setup. I will briefly highlight some options in AutoCAD (ACAD) as it is what my office utilizes on a daily basis and is the one I'm most familiar with (although I do play around in NX7, previously I-DEAS, from time to time).
If you are utilizing ACAD, there are several default templates out of the box that should be sufficient for typical drawings if you are not utilizing a company standard. If none of them are to your liking, you can open one of the default templates (choose a .dwt file under the open dialog); make the necessary changes (add layers, blocks, setup dimension style, text style, etc...), then save it as another name, or back to the template you originally opened. Blocks can be imported at any time, so they don't have to live in your template if you don't want them to. You can change the default template by typing "options", "Files Tab", "Template Settings", "Default Template File Name for QNEW". Under "Drawing Template File Location" is where the default templates are stored on your hard drive with the initial install. Also under the "options" dialog box, there are user preferences which will set the default insertion scale (best if this is unitless, but it defaults to inches).
I setup the initial layers I want for every drawing in the template, along with text style, dimension style and a few blocks for the mleaders arrowheads. It is just a matter of choice on how much you want in your template. Some people put in all of the plot style information as well, which is nice if you are sharing the drawing with others, but start to grow their size accordingly.
Hope this helps some. I would recommend you check out the AUGI Forums, they have some template files there are for free download if you want to see how others have created their personal templates. It may also be a good starting point if you see something you like there, you can customize it more to your liking without starting from scratch.