Hello Tyler,
这 means 'this'
这 本 书 写 得 不 错
zhe ben shu xie de bu cuo.
This book is well written.
( Here the measure word 'ben' 本is used for 书 (book)
这个女人很漂亮
zhe ge nvren hen piaoliang.
This women is very pretty.
( Here is the measure word used for woman (女人 ) is ge (个)
这个 means 'this one'
这 个 可 比 那 个 好 多 了
zhe ge ke bi na ge hao duo le.
This one is much better than that one.