Less experienced writer ready to begin (7)
I believe the answer is:
greener
'less experienced' is the definition.
(I've seen this in another clue)
'writer ready to begin' is the wordplay.
'writer' becomes 'greene' (graham greene).
'ready to begin' becomes 'r' (I can't explain this - if you can you should give a lot more credence to this answer).
'greene'+'r'='GREENER'
Can you help me to learn more?
(Other definitions for greener that I've seen before include "More gullible" , "More environmentally sensitive" , "One recently here" , "better for the environment" , "Like the grass on the other side" .)