Hi biggino,
Many of these questions depends on the specific airline you work for, if you do longhaul or shorthaul, and which country you are in.
Most companies will pay for your training with a few exceptions e.g. Ryanair.
Salary is commonly quite good, considered it's an 'unskilled' job. For a newbe, shorthaul, in the UK, I would estimate around £1250/month after tax. You work hard for it. Most companies do a random roster, and you will only know on roster publication what your days off are going to be. Some companies give you a fixed roster pattern though. Leave allowance is usually pretty good around 30days. Hours....in shorthaul......until you drop over summer, more quiet over winter. But it means in summer you'll probably take home £300 more a month.
Those are just estimates, and not related to a specific company so I would recommend you to inform yourself about different companies, decide on a few that sound suitable to you, and then search this forum and the net to get the airline specific info as it can vary quite a bit.
Hope this helps!