Your package should include salary, healthcare, possibly housing depending on your level, education allowance if you have children. Some companies provide recreation allowance and a travel allowance.
Whilst there isnt tax in Dubai, some countries will insist you pay a contribution of income tax - America for example, but the UK does not depending on how many days you are out of the country.
Housing in Dubai has dropped in price so a 2 bed in the Marina would be around 70,000 AED per year which should include water and electricity. Cost of food depends on what you like to eat and where you want to eat. If you live of toast and jam, then its pretty cheap but if you want to eat out at a 5* hotel every night then this will be expensive, and you need to add in the cost of alcohol if you drink.
Taxis are not too bad to get around - the bus and metro are much cheaper.
I would take a look at a couple of the expat boards such as - http://britishexpats.com/forum/forumdisplay.php?f=60 as this is something that gets asked all the time. about 5 years ago
Firstly, it would depend on your profession and the company that is willing to hire you. So which profession are you in right now? I've been with Emirates Airlines before and their employment package is awesome, it includes almost everything you needed. The things that you need to take into account is the accommodation package, transportation and other benefits for family members.
By the healthcare is mandatory by the government so you don't have to worry about that, so as the return tickets annually, its all part of the basic labor agreement. Bear in mind though that job opportunities in Dubai now are very competitive, unless you are really on top of your game. It's not really a good idea to raise up your bar that early on the recruitment process. about 5 years ago
Check out the rent at www.dubizzle.com
Places to stay are marina, jbr, downtown dubai, these are a bit expensive but its part of the new dubai. The key is to get the rent paid off from the company as the rent is the biggest expense here. Aed 35000 is a decent salary (per month) but it also depends on position and experience about 5 years ago