When and from where I can download Ubuntu 12.04.1 stable release...?

When it is done! ;-) It's expected later today. See https://wiki.ubuntu.com/PrecisePangolin/ReleaseSchedule for the detailed release schedule.

It will be availble at: http://releases.ubuntu.com/12.04/

Remember to MD5 test the ISO you download

Ubuntu 12.04.1 Released here the announce:

----------------------------------------------------------------------------------------------
The Ubuntu team is very pleased to announce the release of
Ubuntu 12.04.1 LTS (Long-Term Support) for Desktop, Server,
Cloud, and Core products. The Ubuntu LTS flavors are also
being released today.

In the 12.04.1 release, we’ve added support for the Calxeda ECX-1000
SoC family, so businesses can prepare for a datacentre dominated by
low-energy, hyperscale servers by testing their workloads
on the new hardware now.

The Ubuntu Cloud Archive also makes its debut - essentially
an online software repository from which administrators can
download the latest versions of OpenStack for use with the
latest long-term support (LTS) release of Ubuntu.

Certified 12.04.1 Ubuntu Cloud images are now available on
Amazon Web Services and will soon be posted to Windows Azure
as well.

This point release has numerous updates integrated, and updated
installation media has been provided so that fewer updates will
need to be downloaded after installation. These include
security updates and corrections for other high-impact bugs, with a
focus
on maintaining stability and compatibility with Ubuntu 12.04 LTS.

Kubuntu 12.04.1 LTS, Edubuntu 12.04.1 LTS, Xubuntu 12.04.1 LTS,
Mythbuntu 12.04.1 LTS, and Ubuntu Studio 12.04.1 LTS are now
available as well. More details can be found in their announcements:

    Edubuntu http://edubuntu.org/news/12.04.1-release
    Xubuntu: http://xubuntu.org/news/12-04.1-release
    Kubuntu: http://kubuntu.org/news/
    Mythbuntu: http://mythbuntu.org/

To get Ubuntu 12.04.1
---------------------

In order to download Ubuntu 12.04.1, visit:

    http://www.ubuntu.com/download

Users of Ubuntu 10.04 and 11.10 will be offered an automatic
upgrade to 12.04.1 via Update Manager. For further information
about upgrading, see:

    http://www.ubuntu.com/download/desktop/upgrade

As always, upgrades to the latest version of Ubuntu are entirely free of
charge.

We recommend that all users read the 12.04.1 release notes, which
document
caveats and workarounds for known issues, as well as more in-depth notes
on
the release itself. They are available at:

    http://www.ubuntu.com/getubuntu/releasenotes

Find out what's new in this release with a graphical overview:

    http://www.ubuntu.com/ubuntu/whats-new
    http://www.ubuntu.com/ubuntu/features

If you have a question, or if you think you may have found a bug
but aren't sure, you can try asking in any of the following places:

    #ubuntu on irc.freenode.net
    http://lists.ubuntu.com/mailman/listinfo/ubuntu-users
    http://www.ubuntuforums.org
    http://askubuntu.com

Help Shape Ubuntu
-----------------

If you would like to help shape Ubuntu, take a look at the list
of ways you can participate at:

    http://www.ubuntu.com/community/get-involved

About Ubuntu
------------

Ubuntu is a full-featured Linux distribution for desktops, laptops,
clouds and servers, with a fast and easy installation and regular
releases. A tightly-integrated selection of excellent applications
is included, and an incredible variety of add-on software is just a
few clicks away.

Professional services including support are available from Canonical
and hundreds of other companies around the world. For more
information about support, visit:

    http://www.ubuntu.com/support

More Information
----------------

You can learn more about Ubuntu and about this release on our
website listed below:

    http://www.ubuntu.com

To sign up for future Ubuntu announcements, please subscribe to
Ubuntu's very low volume announcement list at:

    http://lists.ubuntu.com/mailman/listinfo/ubuntu-announce

On behalf of the Ubuntu Release Team,
Kate Stewart