The MBN Explorer Users' Guide describes how to install and to run MBN Explorer, the software package for advanced multiscale simulations of complex molecular structure and dynamics. This guide includes the description of the main features and the algorithms of the program, the manual how to use the program for specific tasks, the description of all the program commands and keywords, the specification of input information, parameters, files and formats, and instructions on how to handle the program on Windows, Linux/Unix and Macintosh platforms. MBN Explorer is being developed and distributed by MBN Research Center, www.mbnresearch.com. The use of MBN Explorer for non-commercial purpose is granted through low price academic licenses. This licensing agreement is restricted to Universities and Research Centers aiming for scientific publication of their results. Reference to MBN Explorer in reports, publications, or communication mentioning research results obtained with the use of MBN Explorer is required. All details about terms and conditions are available on the website: www.mbnresearch.com Accessible individual and multi-users license agreements are also offered for commercial exploitation of MBN Explorer. Purchased license rights provide access to (i) MBN Explorer software and its updates, (ii) MBN Explorer documentation package, (iii) MBN Explorer user's workshops. Special packages including education, dedicated hands-on training and helpdesk are also available. Contact us or visit our website www.mbnresearch.com for more details.