For layouts
First, you should start reading the official Best Practices multi-screen support . There are many good tips, as well as a general idea of what you need to look for in terms of compatibility.
, , , - . 1024x768 ( res)? , ? , / , .
layout_weight
android:layout_weight , . , , .
:
<LinearLayout android:orientation="horizontal"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<EditText android:layout_weight="80"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<Button android:layout_weight="20"
android:text="Button"
android:layout_width="wrap_content"
android:layout_height="wrap_content />
</LinearLayout>
<EditText/> 80% , <Button/> 20% . , , , .
<include />
, <include layout="@layout/smaller_section" />. , (, ), .