I have a 1996 mustang with a 2005 f-150 engine in it. It has sat in a garage for 7 months without being started,what should i do before starting it?

charge the battery first

Best to use a OBD2 code scanner and check for any stored codes.

A possible fuel pump pressure issue. You will need to have a garage check the fuel line pressure. The engine requires more fuel on cold start and a failing pump may not be able to cope with supply. This may also be apparent at high revs, but not as apparent as cold start.

Could be any number of things. Bad fuel pump, bad fuse, clogged gas line, leaking gas line, faulty electronics to the fuel pump, bad relay. There are a few ideas to start with.

I would be taking a hard look at the Engine Coolant Temperature Sensor. (ECT)

first make sure there is fuel in the tank, then check for voltage getting to the fuel pump,

it likley to be blocked jets,,,try tipping a drop of gas ie:10cc,,only into each plug hole then try starting it up, if it just bursts into life and cuts out again its all down to no gas getting to the engine,,,also engines do dry out if left standing around so the drop of gas will lube the pistons as well

your gas is most likely stale. go buy some octane booster. and some fresh gas and you should be able to get it going again. Spend the extra money and get the good booster. 108 works very well in my classic mustang.

gasoline will go bad! if you plan to store your vehicle use something like "STA-BIL" to prevent this. you may need to remove the gas that is in it and replace it with some that is fresher.

info on sta-bil:
http://www.goldeagle.com/brands/stabil/default.aspx

Local mechanic determined engine was flooded and started it by holding throttle to the floor and cranking 5-7 seconds - then the engine sputtered to life. It has run perfectly before and since and I'm at a bit of loss to understand why this occurred this one time - so far. It's been driven now 5 days with no problems.