Tsukuyomi, Execution of this technique will trap the target in an illusionary world that is totally controlled by the user. The user can then torture the target for as long as desired, inflicting vast mental damage upon the target. Targets of this technique will most likely suffer mental collapse; if they are lucky enough to survive, they will not be in fighting condition for a while. Time is also distorted in the illusionary world: for example, the target will feel the effects of three days when only mere seconds have truly passed. Tsukuyomi requires that the target make eye contact with the user, however, Uchiha Itachi seems to be able to 'force' his opponents to make eye contact with him, probably through the use of the hypnotic suggestion ability of the Sharingan, as he demonstrated when he used this technique on Uchiha Sasuke, who had both of his eyes closed prior to Itachi's activation of the technique, but opened them in a shock/fear expression as Itachi used the technique on him.
Amaterasu, Not much is known about this technique, as it has only been employed once (in jiraiya's frog esophagus). However, we do know that black fire is an aftereffect, and that the technique is extremely strong and can burn through even the strongest of materials, such as the esophagus of an extremely large rock frog (which is capable of breathing fire) that was summoned by the legendary Sannin, Jiraiya.
It has been hypothesized that the third jutsu is named after Susanoo, the Shinto god of the sea and of storms. In Japanese mythology, Amaterasu, Tsukuyomi, and Susanoo were siblings. Since Tsukuyomi is a genjutsu, and Amaterasu seems to be a ninjutsu, one could assume that the "Susanoo" is an advanced bloodline taijutsu.