Update dev docs

DEVELOPMENT.md

@@ -4,32 +4,43 @@
 > to find out about how to contribute to Flux and how to interact with the
 > Flux Development team.
 
+## Installing required dependencies
+
+There are a number of dependencies required to be able to run the controller and its test suite locally:
+
+- [Install Go](https://golang.org/doc/install)
+- [Install Kustomize](https://kubernetes-sigs.github.io/kustomize/installation/)
+- [Install Docker](https://docs.docker.com/engine/install/)
+- (Optional) [Install Kubebuilder](https://book.kubebuilder.io/quick-start.html#installation)
+
+In addition to the above, the following dependencies are also used by some of the `make` targets:
+
+- `controller-gen` (v0.7.0)
+- `gen-crd-api-reference-docs` (v0.3.0)
+- `setup-envtest` (latest)
+
+If any of the above dependencies are not present on your system, the first invocation of a `make` target that requires them will install them.
+
 ## How to run the test suite
 
 Prerequisites:
-* go >= 1.16
-* kubebuilder >= 2.3
-* kustomize >= 3.1
+* Go >= 1.17
 
-You can run the unit tests by simply doing
+You can run the test suite by simply doing
 
 ```bash
 make test
 ```
 
 ## How to run the controller locally
 
-Install flux on your test cluster:
+Install the controller's CRDs on your test cluster:
 
 ```sh
-flux install
+make install
 ```
 
-Scale the in-cluster controller to zero:
-
-```sh
-kubectl -n flux-system scale deployment/helm-controller --replicas=0
-```
+Note that `helm-controller` depends on [source-controller](https://github.com/fluxcd/source-controller) to acquire the Helm charts from Helm repositories. If `source-controller` is not running on your test cluster, you need to tell `helm-controller` where to find it. 
 
 Port forward to source-controller artifacts server:
 
@@ -43,8 +54,47 @@ Export the local address as `SOURCE_CONTROLLER_LOCALHOST`:
 export SOURCE_CONTROLLER_LOCALHOST=localhost:8080
 ```
 
+Alternatively, if your test cluster is already running `source-controller` and `helm-controller`, you need to scale down the in-cluster `helm-controller`:
+
+```
+kubectl -n flux-system scale deployment/helm-controller --replicas=0
+```
+
 Run the controller locally:
 
 ```sh
 make run
 ```
+
+## How to install the controller
+
+### Building the container image
+
+Set the name of the container image to be created from the source code. This will be used when building, pushing and referring to the image on YAML files:
+
+```sh
+export IMG=registry-path/helm-controller:latest
+```
+
+Build the container image, tagging it as `$(IMG)`:
+
+```sh
+make docker-build
+```
+
+Push the image into the repository:
+
+```sh
+make docker-push
+```
+
+**Note**: `make docker-build` will build an image for the `amd64` architecture.
+
+
+### Deploying into a cluster
+
+Deploy `helm-controller` into the cluster that is configured in the local kubeconfig file (i.e. `~/.kube/config`):
+
+```sh
+make deploy
+```