All kinds of large and small organizations are trying to find their place in the Internet of Things (IoT) space and keep expanding the portfolio of connected devices, platforms, applications, and services. But for these components to be able to communicate with each other they first have to be made aware of other components, their capabilities, and possible communication paths. Depending on the number and distribution of the devices this can become a complicated task. Several solutions are available, but the large number of existing and developing standards and technologies make selecting the right one confusing at times. We collected proven solution descriptions to reoccurring problems in the form of patterns to help Internet of Things architects and developers understand, design, and build systems in this space. We present ten new patterns which deal with initializing communication. Five of these patterns are described in detail in this paper. The patterns FACTORY BOOTSTRAP, MEDIUM-BASED BOOTSTRAP, and REMOTE BOOTSTRAP are used to bring information for setting up communication onto the device. Devices can be registered using the AUTOMATIC CLIENT-DRIVEN REGISTRATION, AUTOMATIC SERVER-DRIVEN REGISTRATION, or MANUAL USER-DRIVEN REGISTRATION patterns. During this process, a SERVER-DRIVEN MODEL, PRE-DEFINED DEVICE-DRIVEN MODEL, or DEVICE-DRIVEN MODEL is stored in a DEVICE REGISTRY to digitally represent the device.