kenobee,
the following lines are based on a very brief look at the relevant regulations, so please take them for what they are, just some first thoughts.
The requirement to keep an Operations Manual (OM) and Training Manual (TRM) follows from point ORA.ATO.130 of Annex VII of the Amended Aircrew Regulation (Commission Regulation [EU] No 290/2012 of 30 March 2012) and from point ORA.ATO.230 for those ATOs providing training for professional licences. The content of the manuals, however, is only prescribed in rather general terms and thereby left open to further interpretation. The relevant AMCs (Annex to ED Decision 2012/007/R) give advice on the content of the manuals in more detail, but only with regard to ORA.ATO.230, i.e. for professional ATOs. A look at the draft version of EASA's
User Guide for ATO Manuals (which is targeted at foreign ATOs) might give an impression of what will be required. It seems the breakdown of the OM's contents in this User Guide is more or less a copy and paste job from IEM No. 3 to JAR–FCL 1.055.
I think if I were to prepare an OM and TRM for a small flying club, I would use this IEM No. 3 to JAR–FCL 1.055 as a template. One mustn't forget, though, that IEM No. 3 to JAR–FCL 1.055 applies to professional training organisations, i.e. those that conduct 'approved integrated or modular flying training courses'. One should assume the requirements for small training organisations, like your flying club, must be less stringent. According to the above mentioned User Guide, EASA seem to be aware of this and ask for 'information [...] as applicable to the size, scope and complexity of the ATO'.