Don't apologize - everyone starts with zero knowledge about SQL Server.

If the log file is created very small, it will have to autogrow back to the steady-state size. Each autogrow of a log file entails zeroing out the newly allocated portion of the log, which can be a perf hit on a busy system. Also, unless autogrow is set correctly, you could end up with many hundreds or thousands of VLFs, which can cause a bunch of performance issues too.

Check out my wife's blog post at http://www.sqlskills.com/blogs/kimberly/transaction-log-vlfs-too-many-or-too-few/

Cheers