there's a great cafe in town called kope cafe - try out the treehouse and meet the guys that work there from a local youth program called HEALS. top smoothies too! they were also having a photography exhibition by some local kids when i was there. pretty special stuff!
you can almost get by just walking around gulu, but if it's too hot, you can always grab a boda-boda (motorbike taxi) for about a dollar anywhere. 8000Ush is about equal to a USdollar.
it's better to get your shillings organised in Kampala or another bigger city before you get to Gulu...they do have a Barclays bank but by the time you get into town it'll probably be late - as the bus from Kampala takes between 6 and 7 hours.
Gulu has been quite peaceful for the last 2 years, the LRA activity has lessened considerably in the area, however, some countries may warn their citizens not to travel in northern uganda at present.