I started an online shirt selling company can anyone give me some good advice on ways for marketing? Thanks?

[Jayjay]

NO NO... BIG NO for pop-up banners ! it's annoying and people may think that ur site has spywares and so !

u may start by creating a group on sites like facebook, myspace.. and invite ur friends, and ur friends will invite their friends..so on.
u have to depend on the word of mouth, make some offers, this would really help ur site to be more recognized.. like if someone managed to let about 50 ppl visit your site.. s/he'll get a free shirt.
and when someone visit ur site he'll be asked abt the person that told him about it, and also he'll know about the offer ( inviting 50 people) so the chain will go on. after a while when you feel that your site got popular enough..stop the offer.