There are four images:
- b.gcr.io/tensorflow/tensorflow: TensorFlow CPU binary image.  
 
- b.gcr.io/tensorflow/tensorflow:latest-devel: CPU Binary image plus source code.  
 
- b.gcr.io/tensorflow/tensorflow:latest-gpu: TensorFlow GPU binary image.
 
- gcr.io/tensorflow/tensorflow:latest-devel-gpu: GPU Binary image plus source code.
 
And the two properties of concern are:
 1. CPU or GPU
 2. no source or plus source 
CPU or GPU: CPU 
For a first time user it is highly recommended to avoid the GPU version as they can be any where from difficult to impossible to use. The reason is that not all machines have an NVidia graphic chip that meet the requirements. You should first get TensorFlow working to understand it then move onto using the GPU version if you want/need.
From TensorFlow Build Instructions  
Optional: Install CUDA (GPUs on Linux)
In order to build or run TensorFlow with GPU support, both Cuda
  Toolkit 7.0 and CUDNN 6.5 V2 from NVIDIA need to be installed.
TensorFlow GPU support requires having a GPU card with 
  NVidia Compute Capability >= 3.5. Supported cards include but are not limited to:  
NVidia Titan
  NVidia Titan X
  NVidia K20
  NVidia K40 
no source or plus source: no source
The docker images will work without needing the source. You should only want or need the source if you need to rebuild TensorFlow for some reason such as adding a new OP. 
The standard recommendation for someone new to using TensorFlow is to start with the CPU version without the source.