I suspect this may be a bit of a terminological issue. The Seljuk Turks was a tribal-oriented dynasty that ruled over an area that was largely contiguous with modern Iran and Iraq (i.e. "Greater Persia").

As such the question "did the Seljuks come up with any new innovations" is a bit like asking "did the Plantagenets come up with any new innovations" or, taking "the Seljuks" to mean the wider military-aristocratic class, perhaps something like "did the Junkers come up with any new innovations?"

For they, themselves, the answer is "not really", but for their government and subjects it was an extraordinary time of innovation. Nizam al-Mulk, who was Grand Vizier of the Seljuks from 1064-1092 helped propagate the eponymous "Nizamiya" madrassas, which, although this is much disputed, were a form of higher education that may be compared with medieval European universities. I've written a bit about that here: https://www.reddit.com/r/AskHistorians/comments/35hesi/who_was_eligible_to_attend_the_first_universities/

Administratively, this also helped unite the four primary schools of Islamic law, really for the first time, in what is (disputedly) referred to as the "Sunni revival." The Seljuks also expanded and improved upon the Iqta system which became a highly sophisticated form of tax-farming that allowed urban life to flourish.

The Seljuqs continued to oversee the "Golden Age of Islam's" flourishing of science and philosophy with, for instance, Omar Khayyam and Al-Ghazali (I suppose a kind of anti-philosopher, but no less influential for it).

The trade ties of the empire in this time period I'm afraid I can't recall off hand but I would point you towards David Morgan's Medieval Persia and Hodgson's The Venture of Islam as probably being a good direction to go in.