Metal and wood both swell and contract at different rates and so you need an adhesive which is flexible. You don't say what you wish to join, but probably a contact adhesive such as Evostik would be best.
Depends on the type of wood, the type of metal, the expected temperature range, the humidity, the forces likely to be encountered.
If you supply the information you are more likely to get a useful answer.
I know there are a few ones about but Araldite Standard might be a good option- as i don't know what you are bonding i can't help further but give this a go.
I am not sure what you're bonding but I know Araldite has been around for ages and their Standard adhesive does most jobs. Sorry i can't give you a specific as i don't know how heavy the wood or metal is. Their website might help as well.
I'm having a little bet you're gluing on a cupboard handle.....if I'm right, just bear in mind it will work for a short while then simply come off.....