Most of the answers to your questions are "it depends" I don't understand what you mean by a "software shop" - is this a consulting company, a company that produces a large scale product, a company that produces a small product, an online service or what?
Your ratio of junior to senior developers depends on the kind of product you're producing. If you have an application that has a big, overarching architecture and then lots of relatively simple modules for specific cases, you want many junior developers to pound out those simple modules (e.g. different types of data entry screens).
Coding standards and standardization are always good. For a small shop you're best off looking around for one that you like and adopting it rather than trying to make your own from scratch because it is not a revenue producer and you can burn endless hours in meetings arguing about spacing, comment style, etc. Make an executive decision and move forward.
Tools and languages, again, it depends. Use the right tool for the job.
Since you don't know any of these things or how to make the tradeoffs, what you need is to hire a director of engineering who does because if you try to hire some developers and apply the vast depth of wisdom that you've acquired from this thread on Slashdot you're probably going to fail miserably.