Congratulations! Start retirement savings now - make it automatic, either in an employer plan or by automatic transfers to your IRA on payday. Try for 5-10% of your income, try to keep it up, and in a few months you won't even miss it.

Remember if you invest in a pre-tax plan whatever you put in isn't a dollar for dollar reduction in your pay. Putting 10% in the plan, may only cost you 8% since you'll save on taxes. So, there's no reason even on a budget to not start at some level, maybe 3%, and try to increase your % every so often. Especially if you get an employer match on your contributions.