Report/Chart that shows YTD and WTD per sales person from a single table.

You will need to create a new parent table called "Sales Reps"

Then you will create a relationship, such that each "Sales Rep" has many "Sales"

Then you can create a summary field from the sales table that shows the # or $$ of sales in agiven time period.

You can specify the times by adding conditional criteria such as,
'only summarize data when [date of sale] is during the current year, week, month, last 7 days, etc.

Name the summary fields appropriately and then you have all the ammunition you need to build some great reports.