<p>I'm trying to program ARM using Eclipse + CDT + yagarto (gnu toolchain) + OpenOCD. In several sample projects (from yagarto site for example) I found linker scripts (*.ld) where a lot of linking information specified (along with sections definitions). Actually I haven't faced this files before (IAR doesn't need them), and I find them somewhat difficult to understand from a first glance. So my question is can I use one single such script file for my target processor (STR710FZ2T6) with all my projects or I have to get familiar in writing this scripts and write them for each project. If I can use single file for all projects for particular target processor can you please advice where I can find such universal one.</p>

There is not a universal linker script. These scripts are very important, since they define where in memory (RAM or ROM) the various data and program sections will be placed. There is something equivalent in IAR compilers (xcl files if I remember correctly). You've obviously only used the default ones until now.
There is a nice document about STR7xx called "Using Open Source Tools for STR7xx Cross
Development". You can find a link in yagarto homepage. I recommend that you have a look at it and try to understand how linker files work. There are also some other configuration files that you need to have some understanding of.