I am working on a game engine based on open gl, and I am learning step by step the textures stuff from NeHe's tutorials. Anyway, my dilema is that (as he said) due to technical restrictions his code can't load textures larger than 256x256 well being new to opengl I have no idea how to do this and the title screen for my game looks absolutely horrible in 256x256.
OpenGL doesn't have a "maximum" texture size, but video cards do. Most video cards support textures larger than 256x256, but 3dfx cards (up through the Voodoo3) have had a maximum texture size of 256x256. I'd suggest breaking your title screen into a few different textures and just render them all together.
BTW, you can call glGetIntegerv () to get the maximum texture size of your OpenGL implementation.