The 401K committee does an outstanding job and all of the funds are excellent. However, you are on your own as to what to invest in. There are lots of people that will let you pay them to tell you what to do, but IMHO the only one you can really trust is yourself. We have some asset allocation models that are pretty neat and you can even develop one for yourself that will rebalance itself once a year (that is waht I do).
You can invest as much as you can afford to up to the max contribution ($14,500 I think). This is set by law - not SWA policy. The company matches up to 7.3% so be sure to save at least 8% or you are taking a pay cut. Consider doing this 8% and then maxing out your IRA. As a newhire, you probably won't be able to afford doing much more.
I upped my contribution when I went to second year pay enough to max out as a 2nd/3rd year FO (and I max out our IRAs). It means no new cars or houses into my third year at the company. Talk to the senior guys that you fly with, the money is going to come, but the ability to protect it from uncle sam is fleeting.
Congrats! See you in DAL.