Tax Implications for Custodial Account for Infant (Investment Firm)

I am considering a custodial account for an infant. It will be set up
at Smith Barney. I am told I will receive a 1099 annually.
I assume I will have to file a tax return as custodian for the
baby. I'm interested in how complicated this will be as I am
already doing my own taxes which are fairly complex.
Could anyone give me an idea of the info that would be
involved in filing such a return? I am guessing it would be
fairly simple, but I want to check before I get involved.
Thanks very much for your help!.
Frank
.