Hand soldering is a dangerous process, you can burn yourself, suffer eye damage or lung damage so use eye protection, fume extractors and safe handling of hot soldering irons.
There is a Standard Operating Procedure for soldering at the two soldering stations in the Electronics Workshop, please read and follow the safety directions.
This Soldering Tutorial Part 1 – Tools https://www.youtube.com/watch?v=J5Sb21qbpEQ&t=43s gives a detailed explanation of soldering tools. Using the correct soldering tools helps produce reliable solder joints. Covers all of the safety points !
This Through Hole Soldering Tutorial Part 2 Soldering https://www.youtube.com/watch?v=fYz5nIHH0iY shows you how to solder.
Use a solder bridge witch a very small amount of solder on the tip for more successful connections.
Little Bird Learn To Solder Arduino R3 Ruler https://www.youtube.com/watch?v=eiqPnrKFcZs&feature=youtu.be
The LB-Rule was designed to be your first soldering project. Its oversized pads make it easy for beginners to get started with soldering! Also included on board is a LiPo battery as well as an Atmega 328p microcontroller, the same chip that’s found on the Arduino R3.
Because the LB-Rule has a micro-controller that is Arduino compatible, you can connect an external programmer to it and control both the WS2812 “neo-pixel” and the 7-segment display!
Also a number of the Inputs and outputs are accessible via the pads that have been brought out for you!