docs: Added a readme for nrd.

refs #1463

Change-Id: I157d63b5768eda9e301527106e3f0bfd7af31f6f
diff --git a/README.md b/README.md
index 123b438..469599f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,69 @@
 NRD (NDN Routing Daemon)
 ========================
+NRD works in parallel with NFD and provides services for prefix registration.
 
+For installation details please see INSTALL.md.
+
+## Default Paths
+
+This README uses `SYSCONFDIR` when referring to the default locations of
+various configuration files.  By default, `SYSCONFDIR` is set to
+`/usr/local/etc`.  If you override just `PREFIX`, then `SYSCONFDIR` will
+default to `PREFIX/etc`.
+
+You may override `SYSCONFDIR` and/or `PREFIX` by specifying their
+corresponding options during configuration:
+
+    ./waf configure --prefix <path/for/prefix> --sysconfdir <some/other/path>
+
+## Running and Configuring NRD
+
+NRD's runtime settings may be modified via configuration file.  After
+installation, a working sample configuration is provided at
+`SYSCONFDIR/ndn/nrd.conf.sample`. At startup, NRD will attempt to
+read the default configuration file from following location:
+`SYSCONFDIR/ndn/nrd.conf`.
+
+You may also specify an alternative configuration file location
+by running NRD with:
+
+    nrd --config </path/to/nrd.conf>
+
+Currently, nrd.conf contains only a security section, which is well documented
+in the sample configuration file.
+
+## Starting experiments
+
+1. Build, install and setup NFD by following the directions provided in
+README.md in NFD root folder.
+
+2. Create certificates by following the instructions in NFD's README.md
+
+3. Build and install NRD by following the directions in INSTALL.md
+
+4. Create nrd.conf file. You can simply copy the provided sample file in
+`SYSCONFDIR/ndn/nrd.conf`.
+
+5. Setup the trust-anchors in nrd.conf. Ideally, the prefix registration
+Interest should be signed by application/user key, and this application/user
+key should be used as trust-anchor. However, currently the default certificate
+is used to sign the registration Interests. Therefore, for initial testing the
+default certificate should be set as the trust-anchor. For doing so, the default
+certificate should be copied in the same folder where the nrd.conf is.
+Secondly, the trust-anchor should point to the copied certificate in nrd.conf.
+To know the id of default certificate you can use:
+
+    ~$ ndnsec-get-default
+
+6. Start NFD (assuming the NFD's conf file exist in `SYSCONFDIR/ndn/nfd.conf`):
+
+    ~$ nfd
+
+7. Start NRD (assuming the conf file exist in `SYSCONFDIR/ndn/nrd.conf`):
+
+    ~$ nrd
+
+8. Try to connect any application to NFD. For example, producer application that is provided
+ndn-cpp-dev examples.