Please correct the following sentences if there are any mistakes. many Thanks in advance.

I bough a new phone yesterday and put it for charge. The phone battery was full in charge this morning therefore I plugged it off. However, the phone battery charge was half in charge after 3 hours. I have not used it that much and am not sure why the battery charge has dropped into half. So, I am planning to take the phone to store where I purchased it, they may be able to help me on this issue.

I need to read more to understand the pattern of sentences in English. Whenever I wan to write something first I think in my first language and start to write in English. As a result I go wrong.

I bought three fiction books, cost of $50 yesterday. They are one of the year winner books. I am going to read them every day and write down unknown words which I found when I reading to a separate book. Then I will find out their meaning. This exercise will definitely improve my English.
Please find the attached health Plan as you requested. The document has been updated based on the meeting we had this morning.
Details updated as at 15/05/2011.

My friend told me I am screwing up his English by asking too many grammar questions.

This document is explained the process of stress management plan. The document has been written by discussing with 6 medical professionals.