Welcome aboard. The best way to begin is to search the site for appropriate build threads. Pay close attention to the combinations of parts used in successful projects. Often times mix and match just don't work out well. Most of us have not used any sort of actual "kit", rather a proven selection of parts. Each application will be different based on skill level, budget and the actual engine/trans you elect to use. I suggest that you video the car prior to taking it apart, and detail any sub-disassembly for future reference even though it will not go back the way it started. Pay close attention to methods used by others and follow their map. You may be able to use a great deal of the original chassis and dash wiring integrated with the LS electrics. The tool question is pretty open ended. The short answer is a good set of hand tools will be required. Specialty tools will be dictated by the depth of the overall job you feel confident tackling on your own.
Ask tons of specific questions, search the site, look at the stickys, pay close attention to proven combinations. Most of all don't get in a hurry, be patient and thorough. The group participating here bring a wealth of experience and skill to the table. Most are more than willing to share and will provide encouragement and expertise.