steps for Upgrading from 10g XE to 11g SE...???

Can i inplace upgrade or Back up and restore DB ??

full export to file
setup the new oracle 11 database
full import the file

your export file will be small
and this will be the fastest way.

here is a reference to the export and import utilities
export:
http://docs.oracle.com/cd/E11882_01/server.112/e22490/original_export.htm#BABBHCIE

import:
http://docs.oracle.com/cd/E11882_01/server.112/e22490/original_import.htm#i1023560

Can i use oracle 11g upgrade assist tool   To Upgrade 10 xe to 11g std In GUI

Or Any GUI tool for this purpose???

The 11g Upgrade Assistant should work.  I see no reason why it wouldn't.

For XE, I agree with the above posts:  Export/Import would probably be the best way.

Got can check the following note on Oracle Support for confirm the direct upgrade path:
Database Server Upgrade/Downgrade Compatibility Matrix (Doc ID 551141.1)

Can I Follow the same Step  to upgrade 10 g to 11g   upgrade oracle 10 xe to 11g

http://debaatobiee.wordpress.com/2009/10/17/step-by-step-upgrading-oracle-10g-to-oracle-11g/

Upgrading from Oracle Database Express Edition to Oracle Database

In order to upgrade Oracle Database 10g Express Edition (Oracle Database XE) to Oracle Database 11g, you need to install Oracle Database 11g on the same system as Oracle Database XE and use the Database Upgrade Assistant to perform the upgrade.

http://docs.oracle.com/cd/B28359_01/server.111/b28300/intro.htm