Hi,

The steps on how to integrate Peoplesoft with Salesforce and the supported wsdl types in Salesforce can be found in the link below:

https://help.salesforce.com/apex/HTViewSolution?urlname=Issue-with-WSDL-parsing-while-using-third-party-WSDL&language=en_US

Additional ways to integrate Salesforce from an external Application :


>>You can use SOAP API, Integrate salesforce with external system and update or insert data in salesforce.
>>To integrate Salesforce with external system you need to consume the WSDL from salesforce in your external system.
>>You can get the WSDL from Set Up | Develop | API
>>You can choose any of the WSDL "Enterprise or Partner" and consume and generate stubs.
>>You will get the code of all the calls which you can make from external system to Salesforce.
>>You need to specify the Endpoint URL (The endpoint where you need to make the call)
>>You need to create a webservice and specify the condition when the records would be updated in salesforce.

For more information on SOAP API you can refer the following documents :

1. http://www.salesforce.com/us/developer/docs/api/index.htm
2. http://wiki.developerforce.com/page/Sample_SOAP_Messages_(10.0_API)
3. http://www.salesforce.com/platform/cloud-infrastructure/integration.jsp
4. http://wiki.developerforce.com/page/Integration
5. http://wiki.developerforce.com/page/Integrating_with_the_Force.com_Platform
6. http://www.salesforce.com/us/developer/docs/integration_patterns/integration_patterns_and_practices.pdf
7. https://help.salesforce.com/apex/HTViewHelpDoc?id=integrate_api_rate_limiting.htm&language=en_US
8. https://help.salesforce.com/HTViewHelpDoc?id=integrate_what_is_api.htm&language=en_US
9. http://www.outsystems.com/how-to/integrate-with-salesforce/

Please review the above information and work with with your "PeopleSoft " team in order to set up the Integration.

For your reference, go through below link as well which might be helpful for you:
1.http://salesforce.stackexchange.com/questions/11980/integration-between-salesforce-and-peoplesoft
2.http://stackoverflow.com/questions/4315697/standard-web-services-api-available-in-peoplesoft
3.http://www.youtube.com/watch?v=6L7jvd4rkuo
4.http://www.salesforce.com/assets/pdf/datasheets/Customer_Integration_1Up.pdf
5.https://www.salesforce.com/assets/pdf/datasheets/06.2328_WP_ApexConnect_Integration_0807.PDF

I hope this helps.