I usually go to "Document Library" and then I select Actions: "Modify Settings and Columns"
In "General Settings" tab, I select "Change General Settings".
You will find "Content Approval" item like this:
Content Approval
Require that all items submitted to this list or library be approved by a user with the Manage Lists right.

Do you want to limit it to just the owner uploading, or totally no uploading  at all?

No uploading  for all.

They can just use lists,some webparts.

Do you know how to use caml to make the document library hidden, and remove the creation of document libraries by default?

Maybe this link can help you. This is using JavaScript.

mindsharpblogs.com/.../765.aspx

You cannot explicitly restrict  the rights of the "owner" of a
collaborative My site  (really Personal top level Web in a dedicated site
collection within the Personal managed path). They implicitly have full
Administrator rights, period.

Your best bet is to remove this functionality from the underlying Site
Definition.

If we change existing site  definition are there any effect for existing
WSS Sites ?

You could set the upload size to 0.

Of course if you set the upload size to 0, then nobody will be ablew to upload anyhting to anywhere.

Any workaround for this ?

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The underlying site  definition is an "interface contract" of sorts (like
binary compatibility in COM components). So, you will only be able to
change a site definition under existing Webs in certain ways (primarily
adds and changes).

That said, altering the UI generated by direct-mode pages provides
tomorrow's .NET 2.0 Master Page-like functionality in today's
SharePoint. Of course, only ghosted pages will benefit from these
changes.

You can change permissions for the document library and take away add, edit and delete permissions.

You can also set quotas or lock the site  to prevent adding content. Go to SharePoint Central Administration -> Configure site quotas and locks… -> Manage site collection quotas and locks. Select Adding content prevented to lock the site, OR enter a site quota or select a quota template to keep site from growing beyond a specified size.

But not able to add items in list. I just want to restrict uploads  to document library.

Would removing the Upload button from the toolbar be sufficient?

Let us get some clarification. You refer to adding items to a list
and not uploading  documents. A list does not need to be a document
library, though a document library is a list. You could actually
remove the document library from the site  all together and just have a
site with lists and web parts. Would that solve your problem?

How about uploading  from explorer?

Thanks for our article, seen the article, if we do this, does I think it will affect all sites.i need this upload restriction only for “mysites”

Even if we remove upload button , if they create a new document library
then ??

I don't want user to create a document library, upload into DL,deleting
from DL.

I think this can be relatively easily accomplished by editing the
SCHEMA.XML file stored here:
C:\Program Files\Common Files\Microsoft Shared\web server
extensions\60\TEMPLATE\1033\SPSPERS\LISTS\DOCLIB

Remove any reference to the Upload feature.

You may also want to consider removing the New Document capabilities
too. That is in effect an upload.

There will also be a view with the Multiple Documents Upload link, so
look for that too.

However, when you are all done, people will still be able to use Windows
Explorer to copy files from the file system using DAV. Of course, you
could completely remove the document library list template from the
SPSPERS\XML\ONET.XML file.

Does it affect only "MySites" or all WSS Sites?

Yes, it would only affect "Personal" Webs (the collaborative side of My
Site).

My site  is a single SPWeb with only two pages (default.aspx and
public.aspx) defined by the SPSMSITE site definition. All My Site
collaboration is done using the SPSPERS site definition inside the
Personal excluded managed path.