Brothers and sisters, IHH are an amazing Turkish charity organization and have been and the forefront in assisting Syrians and and many other Muslims in need, I can personally vouch for them. Many of the international organization working in Syria have partnership with them as they have all the logistical expertise on the ground. I have visted their centre in Istanbul and maashaaAllaah many of there volunteers are pious people, kind but also it is a very professional organization.
If you want to donate through western charities then I suggest-
Almuntada- which i have worked with personally (
http://www.almuntadatrust.org/donate/)
Ummah Welfare Trust (UWT)- have a 100% donation policy
http://www.uwt.org/site/default.asp
Human Aid- have a 100% donation policy
http://human-aid.eu/
Regarding clothes, its very expensive to ship to syria, so I would suggest that you donate money as a priority.