These steps1) will leave you with a fully functional bitcoin full node.
curl http://deedbot.org/build-bitcoind-V99995.sh > build-bitcoind-99995.sh
chmod +x build-bitcoind-99995.sh
That's pretty much it, takes half hour or so, spits out an executable bitcoind in ./rotor/TEST2/bitcoin/src
cp ./rotor/TEST2/bitcoin/src/bitcoind ./
You can then run this with something like
LC_ALL=C nohup ./bitcoind -myip=<yourip> -addnode=trusted_node_1 -addnode=trusted_node_2 -verifyall 2>&1 &
There is a list of trusted nodes hosted on this wiki, but you should not rely on it for mission critical situations. As always, GPG is your friend. Ask for a signed list of IP addresses from somebody in your WoT.
If you want to test bleeding edge development code, the Foundation uses own patch management tool, the 'V'. It is still under heavy development - best to learn it by reading btc-dev mailing list archives.
Source code browser (Contains some V leaves, full V support under development).