How do we create a child menu under a tab using salesforce?

I am new in salesforce development,but having 8 yrs .Net exp. completed DEV 401 certification.How do I start the development in SFDC?

I have 2 objects & 20 fields in each objects. Do we have any mechanism to create these objects & fields in one shot, like from xml?

Looking for someone with Salesforce developer skills who would like to work on a client portal project with our nonprofit.  We are in the exploratory stages of this project, and you would have a lot of flexibility and say in defining the project  - Especially interested in volunteers who would like to gain experience, with the possiblity of employment/contract work. 
Respond here or just email your resume and letter of intent to opportunities(at)amhomelife(dot)org  Subject line: SF Portal Developer
 

We need a freelance SF developer that can develop and implement our lead to quote process. Travel Industry experience is a plus. We have existing data schema and workflow mapping. etc. Developer must be proficient in Force.com pages, web to lead Apex, Visual Force, IDE, migration tools, Web Services, third party API Integration. This is the first phase of our project. We are looking to develop an ongoing relationship with a freelance developer.

Looking for someone with Salesforce developer skills who would like to work on a client portal project with our nonprofit.  We are in the exploratory stages of this project, and you would have a lot of flexibility and say in defining the project  - Especially interested in volunteers who would like to gain experience, with the possiblity of employment/contract work. 
Respond here or just email your resume and letter of intent to opportunities(at)amhomelife(dot)org  Subject line: SF Portal Developer