Update CONTRIBUTING.md

Author: twelho

CONTRIBUTING.md

@@ -9,33 +9,74 @@ We gratefully welcome improvements to documentation as well as to code.
 ## Community and Access
 
 Join [[email protected]](https://groups.google.com/forum/#!forum/weaveworks-ignite) for calendar invites to calls and edit access to community documents.
+You can ask questions and discuss features on the [#ignite](https://weave-community.slack.com/messages/ignite/) slack channel.
 
 We also hope to see you at our [developer meetings](https://docs.google.com/document/d/1fv8_WD6qXfvlIq7Bb5raCGyBvc42dNF-l8uaoZzoUYI/edit).
 
 ## Guidelines
 
-TODO: Add contributing guidelines here after we formalize them.
+If you have a feature suggestion or found a bug, head over to [GitHub issues](https://github.com/weaveworks/ignite/issues)
+and see if there's an open issue matching your description. If not feel free to open a new issue and add short description:
+ - In case of a bug, be sure to include the steps you performed and what Ignite responded so it's easy for others to reproduce
+ - If you have a feature suggestion, describe it in moderate detail and include some potential uses you see for the feature.
+   We prioritize the features to be implemented based on their usefulness/popularity. Of course if you want to start contributing
+   yourself, go ahead! We'll be more than happy to review your pull requests.
+
+The maintainers will add the correct labels/milestones to the issue for you.
+
+### Contributing your code
+
+The process to contribute code to Ignite is very straight forward.
+1. Go to the project on [GitHub](https://github.com/weaveworks/ignite) and click the `Fork` button in the top-right corner.
+   This will create your own copy of the repository in your personal account.
+1. Using standard `git` workflow, `clone` your fork, make your changes and then `commit` and `push` them to _your_ repository.
+1. Run `make autogen tidy`, then `commit` and `push` the changes. Just put `make autogen tidy` as the commit message.
+   This (re)generates any new/changed autogenerated content and cleans up the code's formatting.
+1. Go back to [GitHub](https://github.com/weaveworks/ignite), select `Pull requests` from the top bar and click
+   `New pull request` to the right. Select the `compare across forks` link. This will show repositories in addition to branches.
+1. From the `head repository` dropdown, select your forked repository. If you made a new branch, select it in the `compare` dropdown.
+   You should always target `weaveworks/ignite` and `master` as the base repository and branch.
+1. With your changes visible, click `Create pull request`. Give it a short, descriptive title and write a comment describing your changes.
+   Click `Create pull request`.
+
+That's it! Maintainers follow pull requests closely and will add the correct labels and milestones.
+After a maintainer's review small changes/improvements could be requested, don't worry, feedback can
+be easily addressed by performing the requested changes and doing a `commit` and `push`. Your new
+changes will automatically be added to the pull request. (Don't forget to add a new `make autogen tidy`
+commit if needed.)
+
+We also have Continuous Integration (CI) set up (powered by [CircleCI](https://circleci.com/)) that will build the code
+and verify it compiles and passes all tests successfully. If your changes didn't pass CI, you can click
+`Details` to go and check why it happened. To integrate your changes, we require CI to pass.
+
+If you have any questions or need help, don't hesitate to ask on our [mailing list](https://groups.google.com/forum/#!forum/weaveworks-ignite)
+or the [#ignite](https://weave-community.slack.com/messages/ignite/) slack channel. Have fun contributing!
 
 ## Make targets
 
-To compile the `ignite` binary, run
-```
-make
+To compile the `ignite`, `ignited` and `ignite-spawn` binaries, run
+```console
+make build-all-amd64
 ```
 
-To compile the `ignite-spawn` binary and build the Docker image, run
-```
-make ignite-spawn
-```
+`ignite`, `ignited` and `ignite-spawn` are also Make targets if you only need to build specific ones.
+Building `ignite-spawn` binary using either way also automatically packages it in its Docker container,
+and tags it as `weaveworks/ignite:dev` for development.
 
-Before submitting a PR, run
+To (re)generate autogenerated content in case your changes require it:
+```console
+make autogen
 ```
-make tidy
+
+Before submitting a PR:
+```console
+make autogen tidy
 ```
+This will clean up the code (run e.g. `gofmt`) in addition
+to making sure all autogenerated content is up to date.
 
 Other targets:
-- Install the `ignite` binary: `make install`
-- (Re)generate autogenerated content: `make autogen`
+- Install the `ignite` and `ignited` binaries: `make install`
 - Generate dependency graph: `make graph`
   - Depends on `sfdp` (usually found in the `graphviz` package)
 - Push the `weaveworks/ignite` Docker image: `make image-push`