How to get Spinner value?

Spinner mySpinner = (Spinner) findViewById(R.id.your_spinner);
String text = mySpinner.getSelectedItem().toString();

The Spinner should fire an "OnItemSelected" event when something is selected:

spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
    public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
        Object item = parent.getItemAtPosition(pos);
    }
    public void onNothingSelected(AdapterView<?> parent) {
    }
});

Say this is your xml with spinner entries (ie. titles) and values:

<resources>
    <string-array name="size_entries">
        <item>Small</item>
        <item>Medium</item>
        <item>Large</item>
    </string-array>

    <string-array name="size_values">
        <item>12</item>
        <item>16</item>
        <item>20</item>
    </string-array>
</resources>

and this is your spinner:

<Spinner
    android:id="@+id/size_spinner"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:entries="@array/size_entries" />

Then in your code to get the entries:

Spinner spinner = (Spinner) findViewById(R.id.size_spinner);
String size = spinner.getSelectedItem().toString(); // Small, Medium, Large

and to get the values:

int spinner_pos = spinner.getSelectedItemPosition();
String[] size_values = getResources().getStringArray(R.array.size_values);
int size = Integer.valueOf(size_values[spinner_pos]); // 12, 16, 20