No - there are no descriptions of way to install.
I'm not sure to do the rights steps:
=== Download modules-image_gallery ===
wget http://www.silverstripe.org/assets/modules/trunk/modules-image_gallery-r210.tar.gz
tar xzvf modules-image_gallery-r210.tar.gz
rm modules-image_gallery-r210.tar.gz
cp -fr modules-image_gallery-r210 $PRJ/site/modules-image_gallery-r210

=== Download SWFUPLOAD from googlecode.com ===
wget http://swfupload.googlecode.com/files/SWFUpload%20v2.2.0.1%20Core.zip
unzip "SWFUpload v2.2.0.1 Core.zip"
cp -fr SWFUpload\ v2.2.0.1\ Core $PRJ/site/swfupload

=== dev build ===
http://$PRJ/dev/build?flush=all
error in /var/log/php/errlog.txt
PHP Fatal error: Class 'SortableDataObject' not found in $PRJ/site/modules-image_gallery-r210/_config.php on line 2

I think, I need some configure for swfupload too, is it so?
What should be the next step?

The download page for the module makes it pretty clear under "Dependencies" that DataObjectManager and SWFUpload are required. The docs, linked in the "getting started" section of that page explain it, too.

http://doc.silverstripe.com/doku.php?id=modules:image_gallery#installation

You just need to download and install dataobject_manager. Make sure the folders for all these modules are "dataobject_manager", "swfupload", and "image_gallery". The file download likes to append -rXXX to them for some reason and it breaks everything. I recommend using the SVN checkouts in lieu of the ZIP files. It's easier to get updates that way.

SWFUpload is inside of jsparty
/site/jsparty/SWFUpload
Silverstripe 2.3.3

SWFUpload is inside of jsparty
/site/jsparty/SWFUpload
Silverstripe 2.3.3

sorry - the last two postings would'nt save on the right place.

No, it's a module you have to download from the extensions page, or preferably checkout with SVN.

Hello
now it is solved. I load following modules:\\

svn co http://carlinowebdesign.svn.beanstalkapp.com/modules/trunk/dataobject_manager
svn co http://carlinowebdesign.svn.beanstalkapp.com/modules/trunk/swfupload
svn co http://carlinowebdesign.svn.beanstalkapp.com/modules/trunk/image_gallery

and its working fine.

This is great! Thanks Uncle Cheese. That works! I am now trying to include mp3 gallery pages and possibly video gallery pages, but not sure what I need to do. Trawled around the forums, found some interesting posts, but they are missing steps for me. For example, I found a great post here by Uncle Cheese (http://www.silverstripe.org/dataobjectmanager-module-forum/show/260322?start=56#post262570), but if I create AudioPage.php and AudioFile.php and AudioPage.ss, in which directory do I put them? I am new to SilverStripe. Need some help here. Please any assistance would be greatly appreciated.
Also, does anyone who has already succeeded in this, perhaps, have a zip file containing the necessary .php, .ss files required to enable mp3 galleries and possibly video?

Cheers.