www.drjays.com they have baby coogi, mecca, akademiks, sean john, etc... but no jordans you are going to have to shop at baby footlocker, or eastbay.com for that. They have timberland though, and nikes. I shop here faithfully for my little boy he is a bit older but the prices go down a lot and they let you know by email, I like that. Also we all can shop here from infant, toddler, husband and wife.
As someone else mentioned Craigslist may be a good source for free clothing.
A couple other places on-line you may want to try is Freecycle and Swap Baby Goods. Check the Freecycle link below for the group that's nearest to you. You can post what you need and watch other postings to see if there is anything that will help you. With Swap Baby Goods, you can check postings for what you may need. You can also post clothing and other baby items that you have and are willing to trade for items you need.
You can call churches in your area and see if anyone can help you. A church I used to live near would give away clothes once or twice a month. They would have the clothes piled up on tables and you could pick and choose whatever you wanted to take (and as much as you wanted to take). I'm sure they were not the only church to have this idea, and you may find some near you that do the same. If the churches you call don't have programs like this themselves, you can also ask if they know of any place that does. (Just a note: I have never come across any church organization that has refused help to someone because they were not a member of the church [or any church] or because they were a different denomination.) Any church that has food cupboards (gives away food to those who need it) may either have a clothing giveaway as well, or know of someone who does.
You can also try local community groups to see if they have clothing giveaways or know of any place that does.
If you're in the US, you can check the blue pages of your local phone book to see listings of help that is available for different things. If I remember correctly, you may be able to find a listing for groups that will help with clothing.