Well i have been playing on and off for nearly 5 years now but i am really struggling to actually make my own pieces of music, largely because my musical theory knowledge is very, very basic! I am not particularly interested in being able to read music at the moment, but what i do want to do is learn scales, chords, triads etc in much more detail so i can at least begin playing at a level decent enough to attempt to put together my own bass lines. I am a fairly competent player already and consequently am quite happy to improvise when i play and know in my head what sounds right and what doesn't, but i always end up playing very similar things! I imagine improving my knowledge of the aforementioned will help me bit a little more creative.
Basically looking for a good book that will help me with this, and that also may contain recommended practice routines etc. I don't, however, want a book that just jumps in at the deep end and makes me feel like giving up! I am definitely considering bass tuition lessons, but at the moment its a cost i cannot afford