I am working with Sonatype Nexus (Nexus 2.10.0-02)currently. It appears to be a good repository manager providing facility to proxy a repository.
For most of the things you would need Maven Central Repository which comes pre-added and once you have that, I think most common dependencies including spring and hibernate are taken care. I did not try spring-io yet.
So how to get going in quick steps with Sonatype Nexus Open Source version...
1. Download the latest zip/tz file
2. Extract it where you want to have it installed.
3. Start it... mostly you would want to go to bin/jsw and then do a console-* command which is in your 32/64 windows directory.
4. Once you do that, you would see that it internally uses a jetty server (as visible from logs that show up on command prompt)
5. Check http://localhost:8081/nexus
You are done! This is where you would work with... on top-right corner you would see login option, you can login as
default password "admin123"
to explore more options.
In your pom.xml file of maven projects give these tags...
If there are any dependencies in your pom.xml, then this will try to resolve dependency by trying at this proxy location. If it finds it then no download, if it doesn't find then it will try to download the dependency.