However, that then also opens up the argument that surely I should be familiar with ALL religious books etc, as it's not like Christianity is the only option (although admittedly, the discussions/debates/arguments/fist fights I have over the matter tend to always be with Christians).

I would suggest you read sections in small doses, along with some of the mythology of the Greek, Roman and Norse gods.

If you want a critical view, read some science and history on the same topics first.

For example study the formation of the solar system from an accretion disk, Hadean Earth etc and some palaeontology before reading Genesis!

There are reference books on history and archaeology from biblical times, but the bible is not one of them.

I look at the Bible from time to time, and if you have not looked at a section for a few years, the story lines seem to be a bigger heap of drivel each time, although some aspects of human nature and theistic thinking are well illustrated.

Also the reference to "The Bible" is misleading. Not only were the KJ version and RC versions selected from a multitude of earlier texts, but they were repeatedly translated, mistranslated and "interpreted", - as I commented in this earlier discussion. - http://richarddawkins.net/comments/896125