Well, money drying up and borrowing being difficult is what has already happened. The economy relies on endeavour, which is wealth generation. This in turn relies on fluidity of capital, the ability to borrow, lend, and move resources around. In the modern capitalist system, banks are the bodies that do this, but because so many have screwed up, the fluidity has largely disappeared.
Banks are reluctant to lend to other banks, fearing they will lose the loan. This means they won't lend to business or to us, and the economy goes into dead-slow. Consumption decreases as people fear to spend money. Production decreases as people aren't buying and companies can't get day-to-day fluidity. Unemployment goes up, further decreasing consumption. A vicious circle.
Government has three roles it can play:
1) Encourage banks to DO THEIR JOB and increase fluidity to the economy. This means bailing out banks, though this should be with major strings attached so as to avoid similar problems in the future and discourage failure of management.
2) Stimulate the economy by creating work to be done. Large and small infrastructure projects are a good way of doing this, as it creates work for many companies and their employees. It also gets useful things built that would not get done if short-term profit decided it.
3) Provide a minimal cushion for those who have lost jobs. There aren't enough jobs to go round in a recession, so some people, likely many, will not have them. Tax money can relieve suffering, though this should be in a need basis and should not encourage a dependence society. The level of this will depend on how compassionate the society is.
However, all this takes taxpayers money. The sooner the recovery, the sooner is prosperity and major wealth generation again, so it will be a trade off between how much is spent versus how much will be gained. It will be up to the government and the acceptance of taxpayers how much can be afforded - there are no hard and fast rules about this.
If done correctly, endeavour and prosperity will return sooner. People will no longer need benefits as employment goes up. Banks, having learned their lessons, will do a good job and repay government loans over a period of years, with interest. The infrastructure gains will be a benefit to society for many years to come.
If done correctly, that is!